Man you had your whole clandestine system down and everything. If it was summer she wouldn't have noticed cold air. It's easy to get used to all the little things that prevent you from getting caught and feel safe therein, but adaptation is necessary. If you smoke in your room again, blow your smoke through one of those filters made of a toilet paper rool with dryer sheets stuffed inside. It makes your room smell like fresh laundry. Just make sure to suffocate the runoff smoke from the bowl with your thumb before it enters the air. No open windows necessary.