One thing is, if you return her with a bite history, the rescue may be forced to put her down. Liability insurances it seems won't cover dogs with a bite history, which is why most rescues won't take a dog that has a bite history. The other problem is, you know the dog and have a bond with her and don't want her. It is highly unlikely that a stranger is going to want a dog with a bite history. It is always better to return a dog before a bite happens - if there are problems.