:homo:
The hymen has nothing to do with virginity. If you break your cherry riding a horse, the horse didn't take your virginity unless you are in some tropical rain forest and that's how they check your "purity" on your wedding night.
a virgin is someone who hasn't experiences sexual intercourse. This can be coitus with the opposite sex OR sexual relations including oral and anal.
So I would say yes, a girl can lose her virginity to another girl. And Webster's dictionary agrees
i agree as well