I don't see why anybody would be bothered enough to feel the need to say something. Did she really think you were confused about whether she is male or female? "You guys," "kid," even "dude" are used for all genders and ages where I am and nobody cares.
Maybe everyone should just switch to saying "you people." I doubt anyone would be offended by being referred to as a person, but I've been surprised before.
@SooperSarah I should have clarified in my original post. She wasn't "offended"; she's my friend and she and I are both into the nitty gritty of cultural differences. In her world, she would never refer to any group that included at least one woman as "you guys." Her comment to me was good natured, not motivated by offense. But it did cause me to think about this because I do realize it is a northern regional thing. Now, I see from my poll above that it's use as a gender neutral expression has grown!
nor, i venture to suggest, would any of you refer to a group that contained at least one man, as "you girls", without expecting some come back from the guy/guys. and it would be quite reasonable for them to object.
@Yulianna It's pretty widely accepted and understood that "you guys" is gender neutral.
Your question is the same as replacing "mankind" with something like "womankind." One has a generally accepted meaning, even if it's not technically correct, and the other is someone trying to make a point.
@SooperSarah "mankind" has been widely used, but is now more correctly expressed as "humankind" - which is clearly inclusive and gender neutral.
this is not at all the same as "you guys" and "you girls", both of which are gender specific and exclusive. otherwise, i am sure you would agree, it would be perfectly acceptable to address a group of guys as "you girls".