Dude, don't be irresponsible and put a leash on that cat when walking outside. If that cat gets scared while outside you don't know where Nova will run into. The road, a tree, below somewhere unreachable. You never know.
@JuanMena It's ok, it's leash with a stopper. Also, don't worry, I've been trying to walk her for a while, but this is the very first time she actually walk a long shot by herself. She is still too scared to run away far from me