I would shot the doe in a heartbeat. For one thing I have never seen a fawn so small that it can' t survive on its own here in Iowa by the time season rolls around. The second reason is if there is a fawn following you can be completely sure that it is a doe and not a button buck. If you are in need of controlling the population like most areas are the mature does are the ones that need to be harvested. They are the ones that produce the most twins.