What are the legal rights in making one move out of a house who is not a tenant. This is in Texas.?

My brother in law who is a vet and suffers from PTSD invited a lady and two kids to move in with him in anticipation of a wedding next year. He knows it will not work out and wants them out. Texas law states giving a 3 day notice for evictions of tenants, but she really isn't a tenant. Can he lock her out and place her things on the porch? She won't move out.