First I am going to direct you to the thread we started for those who are new to barrel racing. Take a read: Barrel Racing Exercises and Drills.
I talked to the old owners trainer and she was started on barrels she said she was starting to canter them
The first thing that I want to point out is that your horse is started
on the barrels. You horse is not finished
on the barrels. There's a big difference. Your horse is still learning.
but when I bring her around the barrels they are choppy and it sometimes seems like she is stiff around them. what could be the issue?
Do you have a video you can show us? That is the best way to see what is going on.
Most likely, though, your horse does not understand what you want because she is not finished on the barrels. And she does not know how to use her body correctly
in the turn. Again, a video will be better to see what's going on, but I will advise you to work the barrels at a walk and trot first, so that your horse learns what is expected of her and what her body should be doing.
also when you try to do leg cues she just speeds up when your at a walk or any other speed, how do I get her to just move off leg pressure not to just speed up?
It sounds like you have some basic re-training to do FIRST before you attempt to tackle barrel racing with her. (If you read that thread I posted.) You should have 100% control of her body at all gaits: head, shoulders, ribcage, and hindquarters. You should be able to use your legs to control each piece so you can place her body where it needs to go. If she doesn't understand what leg cues are, you are going to have to go back and teach that to her first and forget about barrels until she understands leg cues.
Timing is very important to get a horse good with leg cues. The very instant they give you the correct response that you want, you need to remove your leg (remove the pressure). If you release too soon, they will learn they don't have to do what you ask. If you release too late, they will not know what the correct response was.
Strive to use the smallest amount of pressure that gets you a response.