Anne

MC's mother. Died in a plane crash six years before the story started.
Apparently she and MC's father, Leonard, fought quite a bit. MC and his sister, Melissa, were often sent on sleepovers to Allison's house to spare them from the yelling.

Allison mentions the Anne was 20 when MC was born. Thus she would have been 41 by the time of the story if she had lived, and must have been 35 at the time of her death.