Well she can do 0-340 meters/second in a matter of meters (As seen in S2 finale), so it's going to be a minuscule number. I like how you say that as if it is a proven fact breaking the sound barrier creates a rainbow coloured trail behind you.
No i'm saying that it's been proven in the show that she is fast enough to break the sound barrier and as for the rainbow part well a rainbow trail appears behind her when she breaks the sound barrier.
