Just bought myself an XD 40 service pistol and my wife an XD 40 Sub-Compact. Waiting on the registration process now. Can't wait to go shoot em.
I have a XD40SC. Just a thought, but if your wife is not an experienced pistol shooter who has learned to deal with recoil over time, she may find it to be a bit of a challenge. It is not a beginners pistol. I've been a handgun shooter most of my life, and I find the XD40 to be work to shoot really well. Run a box of CCI Lawman 180s through it and you will see what I mean.
If your wife is an experienced and excellent pistol shooter, then I beg your ( & her) pardon. It's worth noting nonetheless.
Note: Mine has never pinched me.
You do however need to place your thumb carefully when shooting it. If you don't, it's very easy to have it interfere with the slide release and cause it to not lock back on an empty mag.