Deanna Durbin reprises one of her most unforgettable roles in Three Smart Girls Grow Up. Penny (Durbin) has a knack for matchmaking and realizes that her own two sisters, Joan (Nan Grey) and Kay (Helen Parrish), could use her help since one of them is in love with the other's boyfriend. In attempting to manipulate the situation so that both sisters end up with the ideal fiancé, Penny only creates further problems until her father is forced to intervene on her behalf. Often noted as Deanna Durbin's first young adult role, this breezy, lighthearted entry is directed by Henry Koster (The Bishop's Wife) and co-stars Robert Cummings and William Lundigan.