Rule #2134567 -- 96 day rentals are 'way! too long. You should have done something like 15 days, renewable...
Agree 65F is 'way too cold; the OP can't be a real Texan. Real Texans think air conditioning is for sissies and New Yorkers!
I don't know about Jacquo, but on my coast of Florida we keep the house AC set to 79/80. I was in Dallas a couple weeks ago, and the brother-in-law who has lived there 30 years, keeps his multimillion dollar home a comfortably cool 76F.
Get some thermal curtains for that west-facing window and stop wasting electricity on frigid air!
On the other hand, it is your house. If she doesn't like it at that temperature, she can cancel her 96 day stay and go somewhere else, and you'll be out the money. If you want to keep her business, you might want to set the temp at the nationally suggested temp of 68F (which I personally think is far too cold).
There is no Texas or national standards for temperatures in rental properties; that flat out ridiculous! Tell her to go ahead and take you to court over the issue; a small claims judge would laugh the case off his bench!