I'm totally not a gaited person, but it sounds like you're trying to train your Arab to be 5-gaited? If so, the horse is going to have to perform a trot anyways if shown. So I would hold off on the slow-gait and the rack for now, and just learn the walk, trot, canter. Then add the other two gaits once she's learned some balance and rhythm, which I expect are quite lacking from what you've explained.