Clarke is Abigail Griffin's daughter. Before Clarke is sent down to Earth in the Pilot, Abigail tells her to be safe and that she loves her. After, Abigail closely watches over Clarke's vitals. While on Earth, Clarke learns the truth about her mother's involvement in her father's death in Earth Kills. This causes a rift between Clarke and her mother. To punish her mother for her father's death, she takes her wristband off, letting Abigail believe her to be dead. When Raven Reyes makes contact with the Ark in Contents Under Pressure, Clarke confronts her mother and tells her she knows the truth. Abigail tries to apologizes explain his death was never supposed to happen. Clarke truly believes she will never be able to forgive her mother for turning in her father. When Clarke believes her mother to be dead in the Exodus ship crash, she is devastated.
When they are reunited in Human Trials, Clarke is happy to see her but their relationship is strained. Clarke goes behind Abby's back to the point of usurping her authority on numerous occasions. Abby often disagrees with the decisions Clarke makes in regards to the people. Tensions escalate in Coup de Grâce when Clarke tells her mother that even though Abby is the Chancellor, Clarke is the one in charge. In Rubicon, when Abby finds out that Clarke knew ahead of time about the bombing of Tondc, she is appalled that her daughter would do such a thing and begs her to not forget they are the good guys. By Blood Must Have Blood (Part 2), Abby has come to realize the difficult choices her daughter has had to make are not so different than the choices she made on The Council and tells her daughter that maybe there are no good guys.
In Wanheda (Part 1) we learn that Abby has been searching for Clarke for three months, without success. Abby and Clarke are reunited in Ye Who Enter Here when Abby and Marcus Kane travel to Polis to negotiate a peace treaty. Clarke informs them that the only way to prevent a war is for Skaikru to become the thirteenth clan and be put under the command of Lexa. Their indoctrination ceremony is cut short when Azgeda blows up Mount Weather, killing several people. Abby returns to Arkadia while Clarke stays in Polis to represent Skaikru at Lexa's council. They meet again briefly in Hakeldama when Abby helps Clarke and Octavia escape Arkadia, after Clarke visited in an attempt to sway Bellamy away from Pike's influence. In Fallen Clarke sees her mother as she flees Arkadia with Jasper and an unconscious Raven. At this point Abby has taken the chip from Thelonious Jaha and joined the City of Light. Abby and Clarke do not meet again until Perverse Instantiation (Part 1) when Clarke is captured by followers of A.L.I.E.. Abby tortures Clarke so she will tell them where the A.L.I.E. 2.0 is. When she refuses Abby hangs herself in order to force a confession, Clarke still will not divulge the location of A.L.I.E. 2.0. Abby is saved by John Murphy, who cuts her down. In Perverse Instantiation (Part 2) Clarke uses the EMP to fry Abby's chip. Abby is horrified by what she has done to Clarke, but Clarke assures her that "it wasn't her". Abby helps connect Clarke to Ontari so Clarke has Nightblood in her system so that she may enter the City of Light and defeat A.L.I.E.. While Clarke is in the City of Light Abby protects her daughter, even shooting a chipped grounder. After the City of Light is destroyed Clarke tells her mother she is okay.
In the Pilot, Clarke and her mom appear together in when Clarke gets taken out of her cell in prison. She is in panic and Abby comes to assure her and tell her that she has been chosen to be sent to Earth. Clarke gets sedated and wakes up in the dropship.
In Earth Kills, a flashback from 1 year prior to the Delinquents landing on Earth, shows that Clarke, Abby, and Jake had lived an "Apple Pie Family Life". When Jake had found a flaw in the engineering of the Ark, he planned to tell the community but Abby disagreed and informed the Council of his treason. When he was floated, Clarke and Abby were present to see it. Clarke was later thrown in jail for the knowledge of the Ark's flaw and had devastated her mother.
In Murphy's Law, Clark figures out it wasn't Wells who told the council about Clarke's father's plans, but it was her mother Abby. In rage, Clarke gives Monty her wristband to experiment on, telling Abby that Clarke's signal had been terminated. Doing this Clarke makes her mother know how it felt to lose her father.
In Contents Under Pressure, Clarke makes contact with her mother over the radio Raven had repaired and is guided through Finn's surgery by her. After successfully saving Finn, Clarke confronts her mother about her father's death. When Abby tries to defend herself, Clarke says she doesn't want to talk to her anymore and disconnects the radio.
In Day Trip, Clarke is communicating with Jaha over the radio about the Delinquent's status. Jaha then mentions that Clarke's mother would like to speak with her but Clarke declines saying that she'll be passing the radio to kids who actually want to speak to their parents.
In Unity Day, Clarke is devastated when she thinks that her mother was onboard the Exodus ship that crashed.
In I Am Become Death, Raven consoles Clarke about her mom and Clarke discovers she is crying blood and is infected with the biological weapon Murphy has brought into camp.
In The Calm, Clarke asks Bellamy if the Ark has communicated with them but Bellamy says there has only been radio silence. Clarke then comments that maybe her mom was lucky being on the Exodus ship because at least her death was quick.
In We Are Grounders (Part 1), Jaha explains to Abby, Kane, Sinclair and some other Arker's how he intends on getting them to the ground. He then turns to Abby and says, "What do you say, Abby, are you ready to see your daughter again?"
In We Are Grounders (Part 2), once landing on the ground Abby communicates with Jaha and tells him there's smoke in the distance. He tells her to find the rest of their people and in turn to go find Clarke.
In Human Trials, Clarke is being brought into Camp Jaha as a grounder prisoner before Abby reveals that she isn't a grounder and is [her] daughter. When Clarke awakens she is surprised her mother is chancellor and Abby explains Kane gave her the pin when he went to go make peace with the grounders and to get the rest of the kids back. Clarke reveals that it was Mount Weather who took them, not the grounders and wants to go after them but Abby refuses to let her leave. When Bellamy, Mel and Monroe return to camp revealing that Finn and Murphy are searching for her, Clarke is angry that her mother won't send out a search party for them but Abby responds that she can't lose [her] again. Clarke, however, disobeys her mother and leaves the camp with Bellamy to go find Finn Collins and John Murphy.
In Remember Me, Abby consoles Clarke over Finn's death and tells her that the pain will fade and what got her though was loving her. Clarke reacts angrily to this upon realizing her mother is referencing her father's death and claims what she did to Finn is nothing like what Abby did to Jake. She later admits that she and her mother are the same.
In Coup de Grâce, Clarke begins to truly usurp her mother's authority. Notably, she is the one the Grounders listen to and is considered the leader of the Sky People by both the Mountain Men and the Grounders. Abby is upset by this. Clarke later makes her authority over Abby even clearer when she says, "You may the chancellor, but I'm in charge."
In Rubicon, Abby is horrified when she discovers her daughter knew about the missile launched by Mount Weather before it hit and promises to keep her secret safe.
In Resurrection, Abby admits to Kane that she feels guilty about Clarke's actions since [Clarke] is her daughter then tells him that Clarke knew about the missile. She is horrified by her daughter's decisions before Kane tells her that Clarke's choice was similar to the choices they made on the Ark. Later, once she has been saved from the ruins she tells Clarke to remember that they're the good guys.
In Blood Must Have Blood (Part 2), Abby is captured by Mount Weather and her bone marrow is to be extracted. After Clarke kills Dante Wallace, Cage puts her mother on the operating table. Clarke, in the end, is forced to irradiate level 5 of Mount Weather killing everyone in order to save her. When they are reunited Clarke admits that she tried to be the good guy before Abby responds, "maybe there are no good guys."
In Wanheda (Part 1), it is revealed that Abby has been looking for Clarke for the three months she has been gone. However, when Kane offers to send out another search party Abby realizes "they wouldn't find [Clarke] until she's ready to be found."
In Ye Who Enter Here, Clarke and her mother are reunited. However, their time together is cut short when Clarke informs Abby that Lexa wants them to join the Coalition. Abby eventually agrees and the ceremony that brands Skaikru the thirteenth clan takes place at the summit. Once Ice Nation's threat is made clear, however, Clarke decides to stay behind with Lexa in Polis instead of returning to Arkadia with her mother.
In Hakeldama, Clarke is briefly reunited with her mother when Abby helps her and Octavia escape Arkadia.
In Perverse Instantiation (Part 1), Abby who has taken the chip tortures Clarke in exchange for the passcode for A.L.I.E 2.0. Clarke refuses to give it and Abby (under A.L.I.E.'s control) attempts to hang herself to get her daughter to talk.
In Perverse Instantiation (Part 2), Clarke uses the EMP to remove the chip from her mother. Abby is horrified over what she did to Clarke but Clarke tells her that's ok and "it wasn't [her]". Abby then helps Clarke connect to Ontari to filter her Nightblood into Clarke's system so she can take the flame. While she is in the City of Light, Abby protects her daughter even shooting a chipped grounder who tries to attack Clarke.
In Echoes, Clarke and Abby deal with the aftermath of A.L.I.E. for which most grounders blame Skaikru. They find Roan who is alive but severely wounded, but Echo refuses to let Abby treat him. While Bellamy and others distract Azgeda with surrender negotiations Octavia sneaks Clarke and Abby into the embassy. Abby removes the bullet from Roan's chest, he lives and stops Echo from killing Clarke. Roan agrees to honor Lexa's coalition. Abby stays behind in Polis while Clarke returns to Arkadia.
In The Four Horsemen, Abby has returned to Arkadia. Luna and some of her people arrive, they all severely ill with Acute Radiation Sickness. Jackson tells Abby and Clarke that Luna's people became sick when they ate radiated fish. Abby tries to save them without success. At the end of the episode only Luna is still alive and healing because of her Nightblood.
In The Tinder Box, Abby is at Becca's Island when she thinks she see Clarke in the lab, but when the figure turns around it is an image of Clarke covered in lesions, she says "You're running out of time, mom."
In Gimme Shelter, Clarke arrives at Becca's Island, Abby and Clarke hug. Abby explains what is wrong with Raven. Clarke wants to know if Abby is okay, but Abby assures her she is fine. Abby tells Clarke about the possibility of using Luna's Nightblood to save everyone, but they would have to expose someone to deadly levels of radiation in order to test it.
In God Complex Abby and Jackson test the nightblood by placing the thief into the radiation chamber, he does not survive. After more nightblood is forcibly removed from Luna Abby can not bring herself to inject Emori, Clarke takes the needle and injects herself. Clarke wants Abby to put her in the radiation chamber but Abby refuses, she explains to Clarke about her vision, and then smashes the chamber so it can no longer be used.
Jackson (To Abby): Clarke doesn't hate you, Abby. She's just- she's just strong-willed... Like her mom. You gave her that. That's how you're protecting her. And that's what will keep her alive on the ground.