Haha, yay for Crest and Suspiria... I'm loving this whole chapter. It has a whole "show, don't tell" thing going on that really works well and is usually absent when Maytag is around (no offense to her or anything, I'm just saying).
Sure, Suspi's acting different than before, but we haven't seen her for enough time before this to say whether it's "breaking character" or merely just showing another side of a complete personality (because usually people have both bitchy -and- friendly sides to them, you know).
She's definitely getting clingy like the stereotypical girl who has just lost a boyfriend.
She has been through a lot more than just "losing a boyfriend" over the last few days and is entitled to some measure of emotional instability as far as I'm concerned.
So far Suspiria has:
- had to face that despite thinking herself a genius, her best effort to kill Mary still wasn't enough
- seen her boyfriend/best friend BE KILLED in front of her because the spell she gave him to protect himself failed to work
- had to sit there helpless and wait to be killed, when she is used to being incredibly powerful
- had to let herself be saved by the sick girl she came to save
- realized she went so crazy as to try to drop Maytag to her death
- been completely frustrated in her attempt to get revenge
- spectacularly failed the mission she was on and disappointed everyone
- been denigrated and possibly chewed out by her teacher/mentor/boss
- witnessed a fervent declaration of love/PDA between May and Bern a day after losing her own love
So... you're talking about a young person who comes in with the unshakable belief that she is indestructible and the best thing ever, and then has that belief, and pretty much her entire worldview, systematically shattered and invalidated in a short time. Aside from getting the poison out of Bern she has pretty much failed at EVERYTHING she has tried.
If you're going to take all that and turn it into "She's like, teenage girl that, like, totally got broken up with, right?" then I have to disagree, she's nothing like that.