Guardianship over a young adult with Disabilities in Texas

Person of Interest Location: Dallas, TX OP Location: Greensboro, NC

I'm looking to become a guardian for my sister (21) who has autism. She is unable to make decisions for herself so that's why I'm looking for this instead of a guardianship.

God forbid, if something happens where she has no place to live does that mean by Law that she must stay with me?