I have been trying to reduce my use of "guys" as a collective group conveyance or greeting. "hey how are you guys?" especially so when it is a couple of gals. It is an accepted way of saying hi or hello but kind of off putting if you think about it when it is to women, young ladies, or girls.
If I greeted two men or guys as gals "hey gals what's up?" they would be very put off.
More Girl Power! Hiya Ladies how's it going?