What happened to Christopher’s mother? How do you think he felt about her?

We are told very early on that Christopher's mother died two years ago - there was something wrong with her heart, and Christopher didn't visit her at the hospital. When Christopher discovers letters from his mother in his father's room, he realizes that his father was lying. He no longer trusts his father. He begins his journey to London to find his mother, who is living with Mr. Shears. She finds Christopher hard work, and when Christopher and Mr. Shears do not get along, she says she is only just managing to keep it together. At the end of the novel, Judy has moved back to Swindon and Christopher is living with her.