Безобразная Эльза (1981)

The professor's widow Vivi Cassel has three daughters: pretty Irma and Paula and unattractive, but smart, sharp-tongued Elsa, who is humiliated by the condescending attitude of her sisters and mother. She decides to prove that being a woman is much easier than being a person. After visiting a beauty salon, she makes not only her sisters' suitors fall in love with her, but also the mother's fiancé.