Also just acquired an M85 Taurus .38 snubbie, that's +P rated. but there are several brands. Have your wife feel the difference between a +P rd. and a standard one at the range. There is a difference that may be a factor, recoil, hand strength, muzzle flash, etc,..
Federal Nyclads kick at over 800 fps. Great SD round.
http://www.federalpremium.com/products/details/handgun.aspx?id=828Winchester SXT, same as the old Black Talons.
Remington Golden Sabre's 125gr +P.( but they are a big round from a snubbie ) , Cor-Bon, Federal makes a really good one that is not +P rated, 110gr, Hydra-shok JHP's.
For SD, get the good stuff and test it. Muzzle flash is a big factor. The Magtech 158gr ammo had a huge flash. Potential night blindness,...
The top shelf stuff, had minimal flash. As posted, accuracy at 5-7 yds, consistently, with recoil that is not off the hook with a "snubbie". Ability to follow up shots, etc,...Your wife needs to get used to what is comfortable for her also, it may not be a +P rd.
Pay more, (even though it stinks), for top shelf SD ammo, get what you can for the range,,....
In a SD situation, I don't want bargain ammo....regardless of caliber.