Absolutely do not put that Rage on her bow. Not enough energy, not by a long shot IMO. I'm not an "expert" I don't think, just been hunting quite a while. My wife hunts, she shoots a Vectrix at 52 lbs. She is using Montecs and has had good success with them. For lower poundage, lighter arrows that alot of women shoot, I always advocate a cut on contact fixed blade head, like a Montec, or whatever else you choose, but COC is the best choice.
I shoot Grim Reapers, but I'm also shooting 65# and 585 grain arrows, and they perform wonderfully, massive holes, but with that kind of energy, I could push them through a buffalo. Do your gf a favor and get her a COC broadhead that she can have confidence in.