I've been waxing about 2 years now and love it. It was actually recommended by my GYN over shaving.
Definitely get a referral. It takes training to do it right. Your labia can easily get burned. From experience, don't try this at home!
Ask how long ago and where they trained. Are they experienced in waxing the labia or just on top? Ask if she turns the heat down before waxing the labia. The answer should be yes!
I've seen a big difference in estheticians. Some are good and some are not, just like hair stylists.
For what it's worth, we both love the smooth feel, so I will continue to wax.
Mrs. D