Be patient, the gait comes. It may just take a while for it to show.

 

I had success riding with bell boots on (believe it or not). They also sell a weighted strap to go around her pastern when you ride. Just check it often to make sure that it dosen't rub her. Start out with a light weight or the bell boot first. Ask her to collect in then use your cue for the gait. Reward anything that feels different or weird.  Depending on the gait, it can be very energy draining on them (rack and TN. walk) , so don't over do it when starting. My friend, Kelly, had a good book on gaited horses, I'll ask her what the name is and post to the list.