It sounds like she needs to see a doctor. I don't know how you spin that, but for an 18-year-old, I would play it cool. If it is vaginismus, you can't really just force your way in and go to town. You may do some physical damage, and it will hurt like hell. On top of that, it will mess up her head. I don't know if you want to proceed or eject, but I would suggest she see a doctor.
Currently out of office.