I think it seems to take a long time, when really it's two days. It may have been that you scared her. She may have just finished shedding and bam the hide gets moved by something bigger than her. If your husbandry is correct and she's been eating fine (and just shed nicely) I wouldn't worry about it too much. Snakey is sassy sometimes and I've been hissed at before. Happened more when he was younger.