Look either for a clean S56 type/series Beretta or a Miroku made Charles Daly; both 'field' & 'superior' grades [ejector guns] in 20ga. were made within the weight parameters you seem to seek. Either will make a fine field gun for your companion. Neither should require a recoil pad, if they fit her. Pads add unnecessary weight.
I much agree w/comment about a qualified instructor checking fit & some lessons .. best money that you will spend to assist her deriving even more enjoyment from time afield. Nothing succeeds like success.
FWIW, Orvis teaches the 'Churchillian' method of field shooting and can do a good job w/fit. Can recommend 'Robert Churchill's Game Shooting' or 'The Orvis Guide to Gunfitting' by Deck for more insight on said subjects.
Just some thots. Best.
