Mom, from Hold Still, is Caitlin's mother. Her name is Margaret Carter-Madison and she cares for her daughter, but also struggles to deal with Ingrid's death. She knows that Ingrid's death is hurting her daughter but she is, in many ways, ill equipped to help her deal with the loss. In fact, the harder she tries to help Caitlin, the more distant and strained their relationship becomes. At the end, Caitlin realizes what a pain she's been to her mother, and they reconnect.
