Here is what I have done with great results with my wife. She absolutely HATES any kind of recoil....yet she has killed deer with my muzzleloader and a 20 gauge slug gun....all full-punch loads. I simply had her practice with .22's and also had her shoot some low brass shotshell's at targets. She went through the motions of mounting the firearm, taking the safety off and lining up the crosshairs or sights, but never shooting the regular slug or full powder load. The first time she ever shot a full power load in my muzzy was at the deer she killed, and she never felt the recoil. Same thing with slugs in her 20 gauge.
They will never notice the kick when they are dropping the hammer on a deer.