How many nights did you stay at the Inn total, and how many people stayed over? That should probably inform the total. I am guessing $40 is a bit low.
According to Lizzie Post, you should tip a few dollars a day along with a note so that the housekeeper knows you didn’t just misplace a few bills. Tipping each night is important because you get different cleaners per shift. I hadn’t thought of that, and will try to do that in the future.