Get her a good 9mm and start out on sale ammo at ten bucks a box. Te nine will do everything that she needs. Best bet though is a good 38 wheel gun. She would know when it is loaded and empty. Autos have too many issues to think about when shooting.
Ha! I like Gary's idea - it'll be a whole lot safer platform than a semi-auto for a newbie shooter...however, if that idea fails (or you can't find one in pink), the Walther PPK's that I have shot were of good quality, had reasonable triggers, and surprisingly accurate for a short-barreled semi. Haven't seen near the number of negative reviews on that one as compared to the Mosquito...
DA wheel guns are awesome for beginning shooters and there are some good .22's out there. PPK - don't know - maybe a little too small to build good basics. Hey, take her on a gunshow date and see what feels good in her hands. Nothing says "big ol' romantic" like a gun show date. For some reason, my wife is not a romantic, though...
MRS. Rupe can't wait until I get a 2" .357 so she can have my 2" .38, she loves that little revolver and shoots it well. That is what I started her out on and she fell in loove with it. GO WHEEL GUN!
Ruger makes good .22. I have the Mark III. But the P22 type pistol is also very good from what I have seen. Not sure if I'll ruffle feathers but the Barretta Neo is a good inexpensive pistol.