my uncle once beat our neighbors pit bull with a bseball bat........ the dog had attacked his lab (came into our yard to attack him
).... anyways, what im getting at is... you didnt do anything unreasonable... you are a much nicer person than i am, i would have called the police and had the woman cited (i dont know where you live, maybe the laws are different.... but EVERYWHERE here a dog needs to be on a leash)