Is your daughter pulling the 28" the bows is rated at? If so, I'm guessing she is near her limit for poundage, since she only recently started shooting.
Shortening the the bow will increase the weight, especially if you also shorten the unbroken limb to keep the tiller as it should be.
I agree it's the best way to save the bow, but make sure she's not overbowed, or interest may fade.
Just a thought.