Unstolen - Wendy Jean

The thing about being the unstolen one is that you'd better be strong, you'd better stay safe, you'd better not rock any boats or surely they will sink. People depend on you, people who can't take any more stress in their lives and you'd better count yourself lucky because after all, you weren't taken, you're still here and you better be grateful for all that's been given to you because your brother sure didn't get anything . . .
Bethany Fisher's life has always been overshadowed by her missing brother. Four-year-old Michael was abducted when Bethany was a baby and no trace of him was ever found.
Twenty years later, Bethany is a college graduate and has a small son of her own. But her life is thrown into turmoil one evening when her mother follows a man home from the supermarket and savagely beats him to death. What could have made this mild, middle-aged woman suddenly snap?
Packing the emotional punch of The Lovely Bones, this powerful novel explores how the comforting lies we tell ourselves can be ultimately more destructive than confronting difficult truths.