While your snake is in quarantine I would also add in a stick that is angled to allow your snake to rest its head 45 degrees up and down. If it is a respiratory problem, having a stick proper at an angle will help your snake to breathe and get rid of mucus if some does develop.
I would also take your snake to a vet right away to get a proper diagnosis. It’s better to catch it earlier than later. If you find that she is consistently wheezing, and has been ‘sneezing’ then I’d definitely take your snake to a vet ASAP. Even if it ends up being stuck shed, it’s better you checked than wait till symptoms get worse.
I would also take a thorough look through your enclosure after moving your snake to quarantine. There could be something you discover as to why this could occur. Sometimes it isn’t always too high humidity. I’d typically say that 75% is okay, but maybe for your snake, a range of 60-70 would be better. And then bump it up during shed.