Hi Jessica L. hon exactly, most people out there will not understand unless they have done some research on the subject of TS. To some people it is taboo and it is impossible to cross the gender line. As for a second opinion with another therapist, It doesn't hurt if there is a good possibility of it being helpful in relieving your mom's doubts and uncertainties. That was why I also suggested you find another therapist that is, at the very least, knowledgeable as to what being TS means.
It sounds like your mom is just undecided and uncertain and possibly worried about you and what could happen. I will say as in the case of many TS who believe their SO, will stick with them, but very few do. What can one expect from someone who married you thinking they were marrying a (regular) man or what have you at any rate rarely does it work.
But I believe there is a better chance that parent's will accept their child finally when they eventually realise that this is the way it's going to be whether they like it or not. Then they may realize it may be preferable to look at it with an open minded and accept their child in the other gender, then to loose them altogether. At least that is the way I would feel. I had eleven children go under my roof through the years, nephews, nieces, four foster children, and my own three kids.
I loved all of them equally and if any of them would have been born with an extra leg or arm etc or any other of those horrible inflictions we sometimes hear about, may God forbid, I certainly would sigh in relief if a doctor would have told me that one of my kids was TS. I still would not have loved them any less no mater which affliction they had.
I will send prayers that all will work out for you hon. You may even show your mom this post if you wish and you think it might help in some way.
Cindy