Welcome to the site and nice looking pup mate, as for when to start her, it will just depend on when you feel she is ready, i've had pups start at 7 months old and others start at 10 months old.
I normally wait a month before ferreting the setts again, i don't think they abandon them as such more like wait till they know it is safe to go back and yes rabbits can smell ferrets in the sett as that is how you get quick bolters