Question: who killed sara in my sister's grave

title: My Sister's Keeper (novel)
text: Kate Fitzgerald , a frail teenage girl who was diagnosed with acute leukemia at a young age . She is the older sister of Anna , and the middle child out of all three Fitzgerald siblings . She sometimes finds all the attention on her stifling . One of the few times she experiences being a typical teenaged girl is when she dates , and has her first kiss with , a boy named Taylor , whom she meets at the hospital while undergoing chemotherapy . Taylor also has cancer , and Kate has some of her happiest times with him , as he 's one of the only people with whom she 's been able to fully relate , and to speak her deepest , true , feelings about being sick , with . Kate also supports the feelings of her younger sister , Anna , and is thankful for the bodily donations Anna has been made to give her throughout her lifetime . Near the end of the novel , she is the one revealed to have asked Anna to sue for medical emancipation because she was fed up with her mother 's behavior and wanted to die for years . Anna Fitzgerald , a girl who was scientifically engineered in order to be a `` savior sibling '' to her elder sister , and who therefore repeatedly has to donate blood , marrow , and eventually an organ , to her . She is thirteen years old at the time the novel takes place , and seeks to be medically emancipated from her parents , so that she does not have to donate anything to Kate , namely a kidney , against her will , and would thereon have the rights to her own body . She is the main protagonist of the novel . Jesse Fitzgerald , the oldest child , who is dyslexic . Throughout most of the novel , he is a delinquent teenager , but , in young adulthood , after coming to terms with his inner emotions , he goes on to become a police officer , and is no longer rebellious , or desperate for attention , as he was in his teen years . Sara Fitzgerald , the overprotective and domineering `` helicopter mom '' of Kate , Anna , and Jesse . She tries her hardest to keep her oldest , ill , daughter alive and well , and refuses to accept the idea that she is dying . Before the novel 's end , Sara finally listens to Anna about Kate and comes to terms with her choice to die , expressing remorse for her behavior . She is the one who feels insurmountable guilt over Anna 's death . Brian Fitzgerald , Sara 's husband , who understands Anna 's decision to not donate her kidney , but also feels compassion for his wife . He becomes torn between his daughter ( s ) , and his wife , during Anna 's emancipation trial , but ends up siding with his wife during his testimony in court , regardless of his conflicting feelings . He also shows concern for his son , and is the one to confront him about his troubling behavior . Julia Romano , the court - appointed , guardian ad litem , whose job it is to decide what is best for Anna . She also often advises Anna regarding medical emancipation . She and Anna 's lawyer , Campbell Alexander , dated in young adulthood , before he broke her heart . Campbell Alexander , a lawyer who defends Anna as she tries to become medically emancipated from her parents . He believes that she should have control over her own body , and eventually obtains medical power of attorney over her , when she wins her case . He personally uses a service dog , which others find `` mysterious '' , because he does not tell anyone why ; It is later uncovered that he suffers from epilepsy , and that this diagnosis is the reason he broke up with Julia , as he did not believe she `` deserved '' an unwell mate , that she 'd have to look after . Suzanne , Jesse , Kate and Anna 's wealthy aunt , Brian 's sister - in - law and Sara 's older sister of 10 years whose relationship with her is strained due to her overzealousness in keeping Kate alive . While coming to Sara 's aid occasionally due to her wealth , she is more supportive of Anna in suing for medical emancipation . Judge de Salvo , the presiding judge over Anna 's case in suing for medical emancipation