Who is Raina Larkin from Memoirs of a Teenage Amnesiac and what is their importance?

Raina Larkin is James's mother. Since the death of her older son and the problems James has had, Raina is very overprotective of James. Raina answers James's cell phone when Naomi is trying to reach him, so Raina is the one that tells Naomi that James checked himself back into the hospital for help.