The costumes are excellent. According to Kirsten Blomberg, one of the film's two costume designers, she was inspired by Audrey Hepburn and Grace Kelly. Indeed Violet's ensembles are very 1950s inspired with feminine full skirted silhouettes and little scarves tied at the neck. Her right hand woman, Rose dresses similarly. Another group member, Heather dresses more modernly, but still with a similar aesthetic. Lily, the new girl, dresses completely unlike them. She is always in jeans, something none of the other girls seldom if ever wear.
(These pictures are mostly from the other costume designer that worked on "Damsels in Distress," Ciera Wells' website.)