K.,
I have used both tampons and pads and everybody is different and has different preferences. Myself I prefer pads since the tampons sometime feels unconfortable.
I am also a mom of a 7 year old and when the time comes I will let her try both and make the decision herself. However I will be very upset if she does anything behind my back or lies to me.
I think you should approach your mom with kindness and love and ask her why she does not let you use tampons and what are the reasons behind her decision.
For younger girls tampons can pose a risk and I am sure your mom wants the best for you and to keep you safe.
I know what is like to having an overprotective mom and that sometimes suck....but just think that her intentions are good and she is always looking out for you.
I like the idea of talking to your dr since they are prepared to give you the best answer that will fit you.
Also in the meantime you can explore with different brands of pads, some are longer than others, some are thinner than others, I also use for the last days were I have a lighter period the daily protectors. Another key issue is to change them very often so you don't feel yucky.
Good luck!