Do I have a squatter? How to get them out?

[Spencer OBrien]

I have no lease with a tenant I inherited and I am getting paid by section 8. I gave her notice to move out October 31st. They requested to stay until November 7th. Now they are refusing to leave. Do I have a legal tenant or do I have a squatter? What steps within the law can I take to remove them from my property? Can I shut the power and water off after changing it over to my name? I could really use some help! This property is in Dallas, Texas. Thanks everyone! Spencer