This is from a hummer/singer, as well as mother of a hummer. They say his are tics, mine is just an inner tune.
Have you thought about using a physio ball, those big exercise ball. Leave it slightly underfilled so that it takes energy to keep balanced on it. It will build core strength but also provides an non irrataining way for energy to be released. I have two in my classroom. You can see kids just bopping along as they work. It provides another stimulus. She is so young that she would use the small one. When she sits her legs should make a 90 degree angle for the correct size.