Been married 28 years. Get her what she asked for, and reload. As mentioned, the .38 has a different felt recoil, all my daughters prefer shooting it to any of my 9mm.
And I would suggest keeping your eye on the EE for a Model 14 K38 Masterpiece, saw one last week at a very reasonable price considering what you are getting. It is quite possibly my favorite revolver to shoot, or at least dead even with my Python. Love that model 14....a bit more money than the 9mm you mentioned, but your wife will know how much you love her (and yourself too)!