I am in a similar situation as you, except I live in an apt. I just cut a 4 inch hole in the wall near the ceiling through to the other side, which happens to be in a closet, and have a duct fan I bought for like 20 bucks creating the air flow. You can cut another hole at the bottom and even put a second fan in to boost the air coming into the room. That way, you don't have to worry about opening the door to air the room out.
If the smell is an issue, just add a carbon filter to the vent and you're golden.
If your mom knows and was even paying for the light, she shouldn't mind an easily fixable hole in the drywall. The repair materials will cost far less than any supplys you have bought so far.