Any defense gun must be trained with. A gun that intimidates the shooter is one that he/she won't shoot in practice. We may not notice the recoil when shooting for blood, but we notice it at the range, and it is (partially) at the range that we learn how to survive the fight.
A .22 that she shoots well and enjoys is far better than the .38 she dislikes and doesn't carry. Just train for rapid bursts to the head, which is easy with a .22. A .22 in the eye will end most fights pretty quickly.
As I believe Mark Moritz wrote: "The First Rule of Gunfighting is: Have a gun!"
Point taken. IMO, why not have the .22 for target practice and training, occasionally train with the larger caliber used for carry, then simply carry the larger caliber as the SD weapon? Each gun shoots differently, but that would be my plan of action. What's the deal with the .38 special anyway? Every single female I've ever known to carry a handgun had a .38 special. No 9mms, no .40s, no .45s, no mags, just the .38 special.