I wouldn't read too much into what it says online about negative vs. positive gestures. It sounds like she might just be a generally fidgety person, which I am, too. And cracking fingers can just be a habit. Also, when I play with/brush my hair with my fingers, it's generally out of anxiety or sometimes sadness. Well, at times, seductiveness, I guess.

I've brought up my T's body language with him before, like one session where he had his arms crossed the whole time. He apologized and said to let him know if he does that again. He tends to be rather fidgety as well, playing with his fingers, occasionally with his beard or hair. But I'm also quite fidgety, so I wonder at times if it's just a subconscious (or conscious?) mirroring of me. Or if it's just how he naturally is. I'd talk to your T about it for sure. She may have just been having an off day, and it has nothing to do with you.