All depends on what your doing with her and what way she is bred, some breeds mature mentally and physically before larger breeds, dont rush with her at 7 months, let her see the rabbits, if you can take her out with ferrets and mooch the sets, see rabbits bolting and hold them in the net, this will help her settle, dont over do chasing, she has to develope her bone and muscle, pick what you can for her.
I started my little bitch gradually at 10 months, ferreting , until the penny had dropped, which was within an hour, next trip took her where there was myxy and let her hunt up, it stacked