HCA: Hermit Crab Association

so I have a hermit crab that has been buried for about 3 months. this is her second molt with me (assuming she is molting and something hasn't gone wrong). she's currently being looked after by my mom (she was buried when I moved so I could only take one of my crabs with me, and then she's going to come when she comes up) who has been keeping up with all the care. however she is very worried and I'm really starting to wonder if something is up as well. she's never heard croaking, she sniffs the tank multiple times a day to see if she smells the "death smell," and hasn't noticed anything that seems like a problem. the crab has just been buried for a long time.
so I guess what I'm asking is should we just leave it or is it time to start being concerned, and if so what should we do? I know crabs can be buried for that long, but this isn't a big crab at all so I know that's more unusual. So I just thought it would be good to get a second opinion.

I would wait. Wodesorel says she doesn't start to worry until at least the 4 month mark. Is there a chance that crabbo is coming up in the night and going back down?
I always thought that my smaller crab molted for longer than my larger one. Well, a couple of years ago, they both went down within a week of each other. I don't usually even keep track of how long they are down for, but this seemed like as good a time as any to actually count. Well, one evening when I was in the room, Cher was above ground, and hadn't been that morning! I was surprised because she had only been down for about 2 1/2 months at that point. Well, by that night she had dug back underground, and didn't come up for another 3 months. If I hadn't happened to have looked in the tank during those few hours she was up, I would have thought she was under for 5 1/2.