Dr. Hope Martin is the biological mother of Maura Isles and her half-sister Cailin Martin .
Season Three[]
Dr. Hope Martin first appears in "Throwing Down the Gauntlet".
Hope's daughter Cailin is suffering from a kidney disease from all the traveling that Hope and Calin did. She discovers that Maura is her biological daughter and reacting badly, calls Maura a liar and assumes that she is after something. (Money Maker)
Hope contacts Maura asking for her to donate her kidney to Cailin. Hope arrives to the BPD unannounced and sees Angela. They talk and Angela tells her how Maura is "Her business", asking if she is only back to get Maura's kidney. She replies yes. Maura tells her to get an appointment to meet with her, but Hope ignores her and goes to meet her anyway. Maura asks her to leave though. During the chaos of the building collapse, Hope comes to help the injured. At the end of the episode, Maura agrees to give Cailin her kidney, but only if Hope promises to never tell her. (No More Drama in My Life)
Season Four[]
During the beginning of Season 4, Maura learns more about Hope's relationship with Paddy. Both mother and daughter deal with their complicated feelings for Paddy during his trail. Hope's testimony helps put Paddy away for the murder of a cop's wife and son. Thus, gaining respect and penance from Maura.
Season Seven[]
Hope comes back in Season 7, Episode 5 "Shadow of Doubt" to care for Maura after her brain surgery. Hope and Maura work on reconnecting their relationship and get to know each other.
Personality[]
She shows the same level of compassion for her job as her daughter Maura, both believing that they are incapable of saving people but can speak for the dead with their profession.