Well, first, it’s under-rotated. You can tell because she hits the ground with zero forward velocity.
Second, its a rodeo where the first 90 degrees were already completed while riding up the bowl, due to the half-pipe.
So, let’s walk this through. She left the pipe already at 90 degrees, completed the inversion herself another 270 degrees, and then spun what looks like 315 degrees, and landed with zero forward velocity.
By my account, it looks like she rotated 585 degrees.
So, not the first woman/girl to compete a 720.
When you see Hawk’s 900, he’s doing all 900 degrees in his own axis, and the half pipe doesn’t give him anything additional.