Does Trust automatically transfer at age 18?

My niece inherited from her grandfather, her uncle is the Trustee of
the Trust set up for her. She is now 18 years old. She has medical needs
(and also needs a medical mal attorney), has the recalled valve and defibulator recalled by Medtronics. She has needed replacements for 2-3 years, in the meantime - her seizures increase. Uncle/trustee ignors contact with her and her Father (my brother), who has raised her alone, taken 2 & 3 jobs at a time, etc. just to purchase medications, hearing aids, intrepreters, etc. for her. The Uncle/trustee never contacts or sees my niece and believes my brother wants $ for himself. Health Insurance and SSDI will not cover due to her asset, she also will be going to college. Due to lack of response, my niece could die. Is the trust fund accessible to her now that she is 18? Uncle trustee has now hired attorney to have her declared "special needs" just so she can\'t get access to funds. She is not mentally disabled, just physically (hearing impaired, heart, and seizures). Can and how do we obtain documentation and and get the trustee removed - please provide info on what to do. Please contact me at
lydiasgranny@yahoo.com, or by phone: 612-860-4035 or 763-754-3668. THANK YOU!

Laurie Wall