Is she sure she doesn't already have it?

Something like 3/4 of the adult population has oral HSV1, but most of those infected don't know it because they don't recall ever having any symptoms that they recognize as being "cold sores". It might be a good idea for her to get tested if she's worried about it and, as long as she's getting tested, have them test for type 2 as well. I recommend the HerpeSelect IgG for types 1&2. Don't let them do the useless IgM test. It's not type-specific.

She should think about, should she move on from this relationship with you, how will she find someone else that is free from oral herpes since most infected people don't know it.

BTW, my own wife is negative for both types as confirmed by testing recently.