She'll probably shed soon but no telling when. I wouldn't worry if her skin still looks fine, only worry when it's obviously shedding and not coming off. Your humidity is right where mine was when I had my first snake in a tank and the first shed didn't go well. That was almost a month ago and he still has some pieces that I haven't been able to get off with a bunch of soaks.

And that 4 times a year is an average, when the snake is really small and growing faster they usually shed a bit more often. I've been tracking sheds on my snakes but it's not something I think is super important to track. I just do it so if something does come up I know when the last one was.