What word or phrase does your mother always say?
also girl-friend, by 1863 as "a woman's female friend in youth," from girl + friend (n.). As a man's sweetheart, by 1922. She-friend was used 17c. in the same set of senses, of the mistress of a men and of a woman who is a close friend of another.
A best girlfriend; also, a female lover: come here, girlfriend/ look, girlfriend, stay away from him