Does my girlfriend have an allergy to me?

Good night. I had already posted a post similar to this, but since it did not work out and since some time has gone by and the same thing happens, I decided to do it again, but in a more detailed way. So it's like this: I and my girlfriend when we give kisses in the mouth, she spent more than an hour or two after the first kiss she starts to get her mouth swollen and red in the mouth and later she gets huge canker sores in the zone mouth. A doctor from this site told me it could be a perfume of mine or cream, but I stopped using perfumes and the same thing happened, and it only happens on the days when we kissed a lot. When I spend little time with my girlfriend and I give her few kisses, she does not even get any taste, just a small swelling. I would like you to help me in this matter, because it is an embarrassing relationship, I do not know if she can be allergic to my saliva, my toothpaste, I do not know, because I use nothing more than paste when I wash my teeth. I do not know if it could be a virus or her allergy to my mouth because I do not get anything at all. I await your response, greetings, thank you.