Kinetics take a size X nocturnal. If she is going to shoot a 27" to 28.5" shaft at 40-45# with the brass (50Gr) insert, then I would stick with the 500. I think you will have plenty of spine at 40-45#.
What about Easton Axis Nfused arrows? Seems there are some good deals on those on ebay.. What weight (gpi) should she be shooting? The kinetics are 7.6 gpi and the Axis are either 8.1 or 8.9 gpi.
Nothing wrong with the AXIS at all. Keep in mind you will have to use a deep six insert. I was thinking a finished weight of 375-400 Grains with 40-45 pound set up. If you wanted to go with slightly lighter weight finished arrow, you wan use a Velocity Hunter or Xt in 500, I would add another 40 grains via the fact weight and shoot 100Gr COC heads. These are standard (.246) diameter shafts though.
I thought the Axis also used the HIT insert which let you use standard broadheads... My buddy shoots the Axis and his have the HIT system.
If the have and X nock which I am pretty sure they do, then you can use the HITS in either standard or deep six. Sorry for the oversight
No worries. I appreciate all the help. I am planning on going to a SD arrow probably next year as well, but figure she might as well start with them this year while I hopefully bust up a couple more of my GT Velocity XT.. I just can't break those dang things (including putting them into a garage wall, a 4x4, and a 2x4)..