FWIW, "guys" is the default gender-neutral collective term commonly used in large parts of the US, including the west coast, even when the speaker and the collective are all female. The term "folk" has connotations such that it isn't always appropriate, and sounds a bit old-fashioned regardless -- it is not a suitable replacement. If the intent is to gender the collective because it is germane, the common term varies quite a bit with region (most of the women I'm around, raised in big west coast cities, use "girls").

I've lived all over the US and learned to code switch the regional dialects. I've never seen anyone get upset about someone not using the local default collective term in good faith. Trying to get Americans to speak the same version of English is a futile task.