My mouse is missing a foot! :(

Question
Well my mouse, Marilynn has gotten out of her cage a few times since I got her over a year ago. Recently, she got out and we couldn't find her for months. Eventually we did, but only because she ate her own foot! Well that is what we think. We're guessing she started to starve and ate it to stay alive. She could have gotten caught by something and gotten away, but our only pets capable of that are our two dogs, and they're both almost always outside, so we don't think they got a hold of her. If she got caught by something outside, we don't think she would have come back. So anyways, I played with her for the first time in a while (I've been scared I would hurt her; I was waiting for her foot to heal) and I noticed she has a very thin piece of hard something sticking out of her little nub. At first, I thought it was a shred of sunflower seed or something, but I'm beginning to think it is bone. She uses it, kind of like a pirate uses a pegleg. It doesn't seem to hurt her, but I'm thinking it would be easier for her to walk with nothing there. I'm starting to get scared that she is going to get it caught on something and break her leg? Is that possible?
So here is my question: Should I clip it off with finger nail clippers? If not, what should I do? I'm really worried she is hurting.
[[the thing sticking out is about 1/4th of an inch long and its like exactly at the elbow part of her leg]]

Answer
Please do not attempt to take care of this on your own. She needs to see a vet. Attempting to cut it off can severely injure her. She needs to see a vet to make sure there is no infection present. Please get her in as soon as you can. :( As far as her eating her foot because she was hungry...unlikely. Chances are she either caught it in something or injured herself, so she chewed it off. It is ver common in rodents, especially if they're caught in a trap. Poor girl. Please make sure you have her in a secure cage now. I's hate for her to get out again. Let me know how she is doing.