I don't think recoil is going to be too big of a problem as she shoots a 12 ga. just fine
big difference with shotguns vs rifles, especially it is clays you are shooting. shotguns you are in swing the pull of the trigger is more intuitativ, with a rifle you are squeesing the trigger you know.
I have had a gf on the petite side shoot a 9.2x62 and love it, and a heftier girl who shrieked firing a .222
. the petite one had a horrible stance thou because the buttstock was way to long, it is not just the length of pull, the "female qualities" come into play to, especially with shotguns, a rifle it is easier to work around with simple cheeck pad and so on.