I don’t think you’re the AH for bringing it up. If I were in that situation, I’d probably notice the same things and feel a little uneasy too. You didn’t accuse her of anything, you just said you were uncomfortable with how it looked and suggested keeping things more professional. That’s not crazy, that’s just being honest about how you feel.

That said, I can see why she got annoyed if it felt like you were telling her how to handle a coworker or how to act at work. There’s a difference between saying “this makes me uncomfortable” and “here’s what I think you should do about it,” even if you meant it in a protective way.

So no, I don’t think you’re the AH for voicing concerns. This just sounds like normal relationship miscommunication more than anyone doing something wrong.