Shouldn't be too hard to figure out since (a) she's female and (b) her brother is in dental school....
I'm of the opinion that since this is something one is stuck with 24/7/365, it would be well worth having a consult with a very experienced dentist about the problem and getting a referral to someone who can fix it. I recommend Dr. Eloy Barragan. Me, I wouldn't let the original dentist go near me to "fix" it further!!