Lovers and Liars by Amanda Eyre Ward

Children's librarian Sylvie has found love after much heartbreak. Her husband, Alexander, died in a car accident ten years ago. She is now engaged to Simon, a wealthy British man whose family owns Mumberton Castle in the north of England, where the wedding will be held. Sylvie has invited her sisters Cleo and Emma and their mother Donna for a weekend of festivities leading up to the nuptials. The sisters have lost touch, although all three are united in their feelings towards Donna, who was both aloof and self-centered as they were growing up. Cleo brings her boyfriend, Danny, as her guest, although their relationship is on shaky ground because Cleo is in love with her friend, Isaac. Cleo has also been keeping a secret from Sylvie that she should have confessed long ago. Middle sister Emma, happily married with two kids, is not far from financial ruin, which she has not told her husband Rich about. In Lovers and Liars, the sisters bond, confess, and work through their problems together.