Madame and Her Niece (1970)

One of the first films of the legendary Edwige Fenech, made in Germany. The original title of this is Madame und ihre Nichte.
Michelle De Winter has a good life, attending only rich men, to whom she introduces her niece Yvette, who is actually her daughter. Michelle would like Yvette to marry a rich playboy, but Yvette frequents penniless artists and falls in love with Peter.