Sarah Kinney grew up with an abusive father who caused her to have a very harsh view of the world. She distanced herself from her family, including her mother and her sister, Debbie. Because of all the pain she had suffered, Sarah became unable to bring herself to love anyone, whether family or even herself.
Set on making her life her own, Sarah Kinney became a successful and respected geneticist, known especially for her great strides in mapping the mutant X-Gene.
Sarah Kinney was created by writers Chris Yost and Craig Kyle, along with artist Billy Tan. He first appeared in 2005's X-23: Innocence Lost #1.
Major Story Arcs
When the top-secret Facility attempted to recreate the original Weapon X experiment that involved the feral mutant Wolverine, they failed to secure a test subject who could survive the bonding process of the virtually unbreakable metal Adamantium to their skeleton. Seeking to take the project in a new direction, its director, Doctor Martin Sutter, recruited renowned geneticist Doctor Sarah Kinney and tasked her with creating a clone of Wolverine.
The only available genetic sample from Weapon X was damaged though, and they were unable to salvage the Y chromosome after twenty-two attempts. Sarah proposed they create a female clone by doubling up on the available X chromosome. Though her request was initially denied, she still went ahead and produced a viable female subject, prompting Sutter to reconsider. Despite resistance from Doctor Zander Rice, whom Stutter had raised after Rice's father had been killed by a bestial Wolverine at the original Weapon X Project, Sutter allowed Kinney to proceed. As revenge for her insubordination, Rice forced Kinney to act as the surrogate mother for the clone, and so she gave birth to X-23.
Though X-23 was raised in a harsh environment during her childhood to mold her into a weapon, Sarah covertly defied her superiors by treating X-23 as a person rather than a weapon, and reading her Pinocchio to try and give X-23 a sense of humanity.
After seven years, Rice had X-23 subjected to radiation poisoning in order to accelerate the activation of her mutant gene. He then forcibly extracted her claws and coated them with Adamantium. Rice also created a chemical compound he called "Trigger Scent" that would send X-23 into an uncontrollable berserker rage upon smelling it. X-23's services as a weapon were sold to the highest bidder. She was left emotionally stunted as a result.
When Sarah's niece Megan was kidnapped, she took X-23 and had her find and rescue Megan, which she did with ease. This open act of insubordination caused great tension between Sarah and Sutter, causing Sutter to ultimately hand control of the program over to Rice. Rice then however secretly ordered X-23 to kill Sutter and his family. X-23 was able to kill Sutter and his wife, but wound up letting their young son live. X-23 afterwards informed Sarah of what Rice had her do and after learning that Rice was now creating 25 clones of X-23 and was going to separate Sarah from X-23, she knew it was time to flee the Facility with X-23. Before this though, Sarah gave her one last mission: destroy the clones and kill Rice.
X-23 successfully accomplished both objectives, but in the end, Rice had his revenge on Sarah as he had previously sprayed her with Trigger Scent, causing X-23 to go into a berserker rage and mortally wounded her own mother.
Before Sarah died, she gave X-23 a real name: Laura, as well as a letter, a picture of Wolverine and Professor X, and told her to go to the Xavier Institute, hoping for a better life for her daughter. The letter she gave Laura was too bloodstained to read but Laura was later given a copy that Sarah had sent to Wolverine in case she didn't survive. In this letter she detailed everything that she had done to and for X-23, and above all, that she loved her.