This kind of reminds me of the joke that starts like "How many psychiatrists does it take to change a lightbulb." The answer is that it only takes one, but it has to want to change.
I have a hard time believing that your dear daughter can't control the energy in her body just prior to releve'. Most gymnasts learn to start their full turns by sweeping their arms from one side of their body toward the direction of the turn, followed by whatever arm position they're taught to use as they ride out the turn that results from that arm sweep....... so less arm sweep by moving them slower, or through a shorter arc will help.
The reason for my reference to the joke about changing a lightbulb is that all the coaching in the world is useless until the child decides to invest themselves in the changes the coach is asking for. So maybe she can save herself a whole lot of energy by deciding to change something, anything, I don't care what it is as long as she forces a change to take place, but it would be best if her choice was to slow down her arm sweep, or put less energy into that motion.
There's another way to slow down, that classic ballet considers essential to all turning movements, by "spotting" while beginning and ending the turn. This requires the performer to hold their head in the position it's in looking at the end of the beam, or the wall beyond the end of the beam, and turn from the neck down until they're unable to spot the end, or wall. At that brief instant they will turn their head in the direction of the turn until it "catches up" with their body, and passes it as their head finishes the turn well before the rest of the body. When they first catch a glimpse of the end of the beam or wall they'll have a very good sense for how much of the turn their body still, and can place their arms out in a wide crown position to slow down and then stop at the correct degree of turn.
When teaching beam turns, and spotting, I'll tell the kids to follow a sequence of arms, then the body, and then the head for the start of the turn, and the sequence of head, then the arms, and then the body for the finish.
That's all I can do for your dd, the rest is completely up to her, and her determination to change.