My GF does not like revolvers. Of the centerfire I have, she like my 1911 9mm the most. So, I recommend a 1911 9mm (thin grips, short trigger if her hands are small. Adjustable sights would be nice, too).
If 380--- I do not have first hand experience but Beretta 84 (whichever one is the single stack), Sig P230/232 looks good.
Kahr K9 also looks good.
browning buckmark or Ruger MKxxx --- if .22 is OK.