Well circles will help alot just make sure she doesn't get into the habbit of running out...We have had that happen to some lesson ponies because the kids will circle right before a jump so when the more experienced people ride the ponie it thinks it can just run out.
What I use is trot poles before the fence, gymnastics, and stride poles
Trot Poles before the fence.
-set up 4-5 poles a decent amount of length apart and then make a jump
-do this over and over agian making your horse trot through the poles.
-if you keep raising the jump it will also teach your horse to slow down and rock back
Gymnastics (we do them once a month)
-set up 4 bounces to a 1 stride oxer.
-make your horse trot the first fence and then make her/him slow down rock back and bounce every jump then push for the stride and jump the last fence
-this teaches your horse to watch where he/she is putting their feet and when to listen to your legs
-put one pole 1 stride before a fence and 1 pole a stide after the fence
-jump the pole-jump-pole
-this will make your horse slow down and either shorten-lengthen his/her stride.I have a very energetic mare and this will calm her down very quickly. This will also make them think and listen to you and your aids!!!
Hope this works and let us know if you come up with anything new!!!