Gal isn't a word in my vocabulary. I have never heard anyone called "gal".. might be southern thing or something. In fact, I have only ever read the word, I don't think I have ever heard it verbalized..
"Guys" doesn't feel like it relates to gals. If we had a wordsmith in the group, I think it might be more regional.
My female friends call themselves chicks, girls, women.. people.. label doesn't mean much to them..