Also, is it just me or is the "xDD" and "<333" stuff making her apology seem so, so, SO much worse?

I agree completely- because to me, it makes it seem that much more sarcastic and insincere. It's bad enough that it's a "IT WAS A JOKE, PEOPLE, WE'RE TOTALLY NOT OFFENSIVE"-type statement, but they are even making that feeble attempt at an apology into something they're laughing about.