I started going to the gynecologist since I was 14, but I was having a problem that needed to be checked out. I don't quite understand why your mom would want you to go unless you were having a health issue...either way, if she ends up taking you, request a female doctor. It'll take some of the awkwardness out of the situation
I'm a very modest person, and the first time I went to the "vagina doctor" I started getting worked up and began to cry. I was 14. Afterwards, I realized it's not that bad. Explain how you're uncomfortable to your mom. Maybe she'll be able to request one of the better doctors who know how to deal with younger patients?
I hope this helps. If you end up going, get a female doctor.
Feel free to message me any time