you need to be the adult. you have an obligation to your children to make what you believe is the best decision for all your welfare - yourself included. you can be no good to them if you are a wreck. and make no mistake, the modeling going on in that household, the one she wishes to return to, is not healthy for their developing minds and personalities.
you know, even in the most agregious abusive homes, the children always want their parents, and whould choose to return home. this is classic.
she cannot make the best decision; she is three! how can she have the tools that are needed for something so big?
that said, of course she misses her bed, her daddy, the normalcy that is now absent. things change, and we adjust. it's part of your job to assist her with the adjusting.
you can do it.