Hi thanks Hops and Phoenix.
To answer the question, NM controls all, legally or otherwise, there is nothing for me to challenge.
Dad passed in 2000 and until 2008, NM maintained that he had no will, nothing for us to inherit, she claimed he had made bad investments and made other claims to manipulate into believing her story of "poverty" as a means to mislead us and prevent us from asserting ourselves or asking for anything. I believed her. Her actions also were in line with that. When he passed, they were in the middle of a kitchen remodel, the day after he passed, she paid the contractor and then fired him, leaving the kitchen half finished. No working oven, no floor (just painted concrete), no running water in sink or laundry room adjacent to kitchen. And its been that way since 2000. At Chrismas time or birthdays she might give me a check and would tell me to "do well" with it as she was not sure how long it would last. She has been manipulating and controlling the money on purpose. This is a financial issue compounded by her Nism, so appeals to business or rational money management do not work with her.
Now, the problem is that even when I want to do things to advance myself, she discourages that as well, even if I were to finance it myself because she fears my failure would pose a financial risk to her. This is where I thought T could help with boundaries and allowing me to take the right risks as an adult.
Even if I was self sufficient right now, I know from previous experience how demeaning she is and how discouraging she can be about me making my own decisions.
Thanks to all for the posts, its a relief for me to come here and get understanding and support. All the best to everyone.