While I most assuredly agree with letting her pick her own gun and going to a range that rents them, I will make a suggestion.

I bought my wife a 640. A stainless version of the 642 and 442 that weights about a .5 lb more. The extra weight makes the felt recoil when shooting .38 specials not feel as harsh as it's Airweight brothers. It's a DOA, so the ability for her to be able to shoot through her purse is an extra added benefit. She wouldn't even need to draw the gun if it's use became necessary. Hope this helps!