I understand you wanting a smaller sized youth-type stock for a person of smaller stature. But don't think that this will make the gun a whole lot more comfortable to shoot. Fit is extremely important but a smaller and lighter gun will allow the transfer of more recoil. If this is not a concern and price is not a concern I'd take her to the retailer with the largest selection and have her shoulder as many as possible. Then, if you belong to a gun club, ask around to see if anybody has some of the modelsshe found comfortable and you could probably get a chance to have her put some rounds through several styles and types.
You mention many nice guns, but a Winchester featherweight in .260 OR 7mm/08 would be a sweet package. And then it would be worthwhile having a competent smith fit the stock to her custom.