Unstolen - Wendy Jean, Pan Macmillan

Bethany Fisher's life has always been overshadowed by her missing brother. Four-year-old Michael was abducted when Bethany was a baby. 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 beats him to death.