Slum
Cephalexin or augmentin would cover her better for pasteurella canis( nasty bacteria in a dogs mouth). Not sure how hard that would be for your to get your hands on for a dog?? Augmentin would be the preferred. The peroxide is likely killing the healing granulation tissue as well as bacteria making it very hard for the wound to heal up. Start using just soap and water Instead and see if it starts getting better.
Hopefully your dog turns the corner soon!
