Molting Advice - How long before I should get worried?

Ok, so this is my first time with a spider molting and I'm starting to get nervous. I last saw her outside her hide around February 20, so just over 2 weeks ago. After I saw the excessively thick webbing inside the hide, I knew she was likely molting, so I started making sure the humidity was between 70% and 80%. Occasionally, I've seen her poke her head outside the web, but still well inside the hide, such that I couldn't see her without a light.

One thing I've neglected to do since then, though, was mist next to the hide so she can drink, which I just read in the keeper guide that it's recommended, how worried should I be? I did it once or twice since she retreated at first, but I didn't realize how important it was until just now when I read the guide again. I've started doing it regularly now, even made sure to put a wet q-tip right next to the hide entrance for easy access right now, but I'm worried that it's too late and she's retreated for good and is molting while dehydrated.

What's the standard accepted maximum for the amount of time they're retreated in their hide without any sight of them before they die? Just want to know how likely it is I'm going to get a mismolt and how long it should be before I'm certain it failed.