The correct way to measure trigger pull is in an article in the Knowledge Base, which is for Supporting Members, but PM me and I will walk you through it.
The ideal choice would be to whack the stock a little shorter than she needs and add a very good quality Recoil Pad, like Decelerator or Limbsaver, to ease the felt recoil on the poor woman.
Would cost about one hour of time ( $75 ), plus parts, in our shop.
JD