the first time my t molted, it was already done before I noticed. I was able to watch my entire adult G. rosea molt. I didnt worry because she popped (her carapace) after 6 or so hours. What species is molting?
I only worry when my G.Rosea pulls a fast one on me and flips over with no prior warning - sometimes she wont bother fasting or building a moult mat or give any other indication that she's about to moult, and thats when I'm most likely to have a moments' panic. It can be quite a shock to look in your tank and see them unexpectedly upside-down, especially when they were plodding about as normal just 10 minutes before.
yeah I was pretty nervous with my G. aureostriata juvenile. I got her in premolt and spent the next three weeks waiting for her to do her thing. She blocked herself in her hide and I lifted it up one day to find a spider twice the size of my old one. It was pretty neat.