I hope you can get her back to good health

I think I'd put the bell back, it's nice to be able to keep an eye on her but it could stress her out if she has nowhere to hide.

What food are you giving her? I'd be tempted to try a little bloodworm if she won't eat any pellets. I guess she could also be startled by someone trying to hand feed her after so long, if you leave the food in there for 10 minutes or so does she not touch it at all?