[Hunt'EmUp]

When I was training for Seasoned (and still, since I run a bunch of Upland, too), I would walk with a bumper and the dog at heal, and randomly throw it with no whistle and no "sit" command (of course you'll have to say sit in the beginning). He learned that he had to stop whenever a bird is in the air and not go until released.

X2 but use a hidden station and a real bird, maybe even a live flyer (no whistle, no sit, you want the correction). Then before releasing her back up and get a heel correction. This does two things, enforces the sit-heel and provides you with a tool you can use during a test, you can back up, training her to move back with you can stop the break