I don't think he anticipated that allowing her to hang around would result in his brutal death.
Whether or not she was invited, and whether or not Travis knew she was coming - I think it is clear that at some point, at least, she was there with Travis' permission.
That does not mean that she wasn't psycho or that she hadn't stalked him or that she did not show up unannounced -- it means Travis used bad judgment and instead of calling the police to have her removed, he allowed her to hang around and then kill him.