Peroxide is okay if that is all you have, but only use it once--it will not hurt as the first cleaning. But plain old dish soap (Dawn, Palmolive, etc) and warm water will also work. You will need some plain Triple Antibiotic ointment to use if you can go to the store later. It will help in wound treatment, and keep any flies away from her. How is she doing? Awake, alert, drinking water? What do you have for your own first aid needs?