I understand the need for fresh air flow when it is hot. Just tell the Good Lady she has choices...have a 30-foot wall built around the house (discourages climbing through open windows), have a couple of guard dogs roam the yard at night, or install iron bars on all windows. If she doesn't like those options she will just have to live with being hot or come up with alternative solutions.
She would probably love a wall. That might not be best to suggest :0D
I have created my own little Aircon unit with an old plastic carton asked a cooking can from a PC. I am laughing!