I must say, I'm quite jealous if your local pet store sells PAM! I can only find it online, it'd be nice not having to pay $10 just for shipping, lol. Just be sure you follow the direction very carefully to prevent any problems with your snake as it is a pesticide, and do a follow-up treatment to ensure all eggs have been killed.
Slightly higher humidity isn't necessarily bad as long as the subtrate doesn't remain moist at all, which could cause scale rot. 52% is fine though while not in shed. That size enclosure should be able to house her for her entire life. She's obviously not stressed about the amount of space if she's eating regularly. Glad I could help, I hope the PAM solves this soaking problem. If not, hopefully you or people on here can help you figure it out because constant soaking is not normal at all. Good luck!