@RazMan. The gunsmith advised against swapping out the spring due the possibility of the fact the pistol may not fire. They sold her a Walther PK.380 and she was surprised how effortless it was to rack the slide.
I expect your gunsmith gave you good advice. Reducing the spring strength makes the hammer fall with less force, perhaps not enough force to ignite a primer. The PK380 is a good choice, and if she can effortlessly rack the slide, it's an even gooder choice. ;-) Best get her out to spend some significant chooting time, though. I mean, if she's going to use it on you, you want to know whether she can hit what she's aiming at.