[krackersmom2]

In the photo it looks like she is in the water. Is she voluntarily in the salt water dish? If so this could be a sign a molt is imminent.
A hole in the shell is not ideal....the shell is where they store up water and the shell helps keep their abdomen moist. I had a large crab that cracked a hole in his shell. He went down months ago and I haven't seen him since. My presumption is he didn't make it, but I also don't want to dig around and possible interrupt a molt either

Take the feeding advice and give your crab plenty of shell choices. Hopefully she will choose a new shell soon.