"I mean, she does start out having that kinda shitty "be careful around that girl, I've heard she's gay" attitude in the beginning"
While this is pretty shitty, I'm pretty sure she didn't mean it that way, she's just obliviously insensitive. What she meant is "careful, she might not see your relationship the same way you see it". Of course I'm only speculating, but her reaction to them as a couple seem to point to it.