Complex sentence: Sophie's mother Donna, who owns a villa, is ecstatic to reunite with her former Dynamos bandmates, wisecracking author Rosie Mulligan and wealthy multiple divorcée Tanya Chesham-Leigh, and reveals her bafflement at her daughter's desire to get married.
Split into simpler sentences: Sophie's mother Donna, who owns a villa, is ecstatic to reunite with her former Dynamo band mates, a wisecracking author named Rosie Mulligan and a wealthy multiple divorcée named Tanya Chesham-Leigh. Donna reveals to her friends her bafflement at her daughter's desire to get married.