This is probably much too late to help, but I've got a thought here that's a little different. Her problem with overrotation is starting way back in her first phase take-off. I would coach her to be a little flatter here, giving up distance by way of height for perhaps slightly less distance by way of speed and with more forward and less downward momentum going into phase 2. Secondly, after take-off in her first phase, her support leg is not quite pulling through all the way. I tell kids that when they're on a skateboard, they can't just put their foot straight down and push and expect to stay upright. They've got to get their foot out in front and get it coming back underneath them, and the faster they're going the more they need to create that "negative foot speed." Without requisite negative footspeed, the top of the athlete will keep going while the bottom (foot) slows down, creating rotation upon landing.
The thing with this kid on film is that she looks like she may be pretty dang fast, and while speed is a really good thing, if you don't have negative foot speed to match your speed, then you are going to be exacerbating the problem. She needs to work on being flatter and pulling that support knee through in a more pronounced way…and if she's flatter, she won't have the look of someone who's reaching for the ground as it appears she is going into the landing for phase 2.
I suspect if you can clean up those things, the problems she's having late in the jump may solve themselves to some degree. In other words…you're right, she should go 11.5 meters +. 🙂