Here is an important key point to remember when it comes to cheerleading, "Wait for your flier!"

Wait for her to begin to stand up out of the basket, wait for her to jump off of the ground for stunting, wait for her to push off of for the walk in, wait for her to flick for the toss in a COED stunt, and wait for her to get over her bases in an all-girl ground up stunt. 

If you do not wait for the flier, then either your stunt/basket will not be as strong OR the flier just will not get up.  Remember this next time you have problems..