More than likely the other children have taught her to scream, next time she has a lot of children around take a look when they dont know you are around, it sounds like learned behavior.
sounds like it's working really well for her, Lece. She's getting exactly what she wants every time.
With a total of 7 other children around constantly, she's found how to get attention - by screaming. She's found the exact pitch and volume that gets a response every time.