I AM ADOPTED AND MY ADOPTED DAD'S SISTER'S DAUGHTER AND I WOULD LIKE TO MARRY. IS IT LEGAL IN TEXAS?

Under Texas Family Code, Section 6.201, you may not marry, despite the adoptive issue - blood or adoption makes no difference. You are related. ...

Well, it's a good question, though the law is pretty sound there - i.e. wrapped up. What I mean is that any location may request the police issue...