A surprisingly small amount of horses are truly engaging the hqs at any gait- before you can expect her to do this at the canter you need her to be able to do it at the walk and then trot first. She needs to develop the proper muscles of carrying herself correctly. Not only is this very beneficial for the horse, you'll get that all-round togetherness look/feeling instead of just a headset.
Do a lot of work at the trot. Circles in and out and lateral work will encourage her to stretch down and forward. You also have to get a bigger trot from her (if you don't feel that the one she's at is truly engaging herself, I don't know, haven't seen her work) and by this just ask her to extend it more than her usual stride while working on the bending. Biggest thing to remember is timing and tempo, sounds like she naturally has that ability which gives you an edge in training.
It's really a lot to explain over the interwebs, probably a good idea that you get a trainer to help you with it! Good luck with showing, have a blast! :)
We are not human beings having a spiritual experience. We are spiritual beings having a human experience. -Pierre Teilhard de Chardin