Okay, first of all your cousin's doc is not giving the most accurate info about the herpes (not uncommon among doctors, unfortunately). No one can know if herpes (any type) is in a dormant state, since the herpes virus goes in and out of a dormant state all the time. When it reactivates it sometimes produces a visible outbreak (blisters, rash, redness, etc.) but not always. Sometimes it becomes active and the person could be shedding the virus but not know it because there are no symptoms to indicate that it's active. So it's misleading to say someone's herpes is dormant just because they're not getting visible OBs.
What you describe sounds more like canker sores which are not typically caused by any kind of herpes virus. In fact it's not known for sure what causes canker sores. Do an Internet search on them and you'll find info about them.
I have no idea if your cousin's birth control pills have had any effect on these sores. She'll have to talk to her doctors about that.
There are actually 8 types of herpesvirus, although only 2 types of herpes simplex virus (HSV). Other herpes viruses cause things like mononucleosis, chicken pox/shingles, roseola and Karposi's Sarcoma. However, having one type of herpes does NOT make you more susceptible to getting any other type. And in the case of HSV-1 and HSV-2 they can actually provide a bit of resistance to getting the other type.
As far as HSV-1 versus HSV-2 is concerned, they are almost identical. HSV-1 is most often found around the mouth area and breaks out in the form of cold sores usually. HSV-2 is most often found in the genital area and symptoms typically are blisters, redness, rash, tiny sores, etc. It is possible to get either type in any location, but they seem to prefer (be most at home in) the locations I've mentioned. HSV-1 tends to be somewhat milder in its symptoms than HSV-2, and getting one in the other's preferred location can often produce milder symptoms, but this can vary greatly with the individual. And it's possible to still have either type and yet not get any symptoms.
I also want to do a bit of my usual rant about the myth that if you have herpes you must be promiscuous. It is true that the more partners you have, the more you increase your chances of getting herpes or other STDs, but it is not therefore true that if you have herpes you must have had many sex partners. You only need to have sex with one person one time to possibly get this.
And as much as 30% of genital herpes is actually HSV-1 caught from receiving oral sex from someone who has HSV-1 orally. A huge majority of the population (50-90% depending on your source) has HSV-1 orally, usually caught in childhood through non-sexual contact with family and friends. So please don't make the assumption that you have to be sexually promiscuous to get this.
Okay, I'm done.
I hope all this helps.