I'm too hot, she's too cold. What do we do?

Last night, my pal came over for a sleepover and turned up my heat to 77. I keep it on 68. I was grateful when she left in the middle of the night, per air mattress deflating, so I cold turn it down. She can add layers, but I can only open the window, and take off so much. Do you think it’s rude to mess with other folks thermastat? I want to tell her to learn a manner or 2.