Thanks pat - boils down to "if she can get sideways on purpose, and correct it, she is less likely to panic when it happens on accident
When my daughter was learning to drive, we did the same thing. Went to the High School during Christmas Recess when they hadnt cleaned the big parking lots and they were void of any cars. I brought along some cones and would set them in specific areas.
Put my daughter behind the wheel and I sat int he passenger seat. I'd have her get up to a typical speed, say 35-40mph and as she'd pass one of the cones, I'd rip up the emergency brake without her knowing when I was going to do it. I'd have her try and correct the car without hitting the next cone that was placed a bit in front of the first one.
We did this for an entire day till she could correct it almost 90% of the time.
I then would have her practice just drifting through the corners of a set-up apex turn with using the emergency brake to control the spin as the car would brake traction
I dont know if this was a good learning tool or not because my daughter is now a cocky driver and likes to show off with how she can handle a car??? But knowing that she can handle it is safety for my mind