I'm kinda in the same situation only, i told my parents i'm growing hemp, and i showed my mum on the internet that hemp is legal coz she thinks their both the same. So now everythings cool, i said i'll still smoke it and she didnt mind. My dads always in a different world so he don't care.
I'm growing in my bros room who is helpin me out. To stop the odour i use a timed air freshener. I'm also growing chillis, herbs and tomatoes as they'll give off different odours, plus its making my parents appreciate it as i'm giving them the plants. I bought a low smelling strain and also open a window so the problem of smell is GONE!