Yeah it's her place so you have to respect that if she doesnt want it to happen you shouldnt do it. Also what kind of area are you living in? My best friend lives with his girlfriend in an alright flat, thing is its beside a crappy estate and nextdoor to a pub. Some people broke into the flat once so they could go through and break into the pub. My friend didnt wanna phone the police because he was in the middle of growing and didnt want his crop being snatched.
No other possible places you could grow?