Canker sores are not contagous...but cold sores are, so you need to be very very careful. It is a different form of herpies than genital herpies, but oral and genital can be passed back and forth. It most likely is a cankersore, i've never heard of getting a cold sore on the inside of your mouth. But if there is any doubt in your mind then don't put your mouth near her vagina.
