Several people can put a muzzle brake on it that will help, and there are a couple of recoil-reducers available on the market.

http://www.probed2000.com/ is a guy that does a good job, but you did not say that the wife wants to hunt with it.

If she just wants to shoot it, without getting creamed...try putting a 10 pound bag of lead shot on her shoulder and use it like a p.a.s.t. shield. That will really dampen the recoil.