Kahr PM9? ...a little pricey but nice. That's about as small as 9's go... Otherwise you're into the 380's which are really having a resurgence now (I hope I'm not sounding like a broken record on this site)... especially with the Ruger LCP and the new S&W Bodyguard 380.
Genitron.com: Details for Kahr Arms PM9 9mm Luger Pistol
Genitron.com: Details for Ruger LCP .380 Automatic Pistol
There are many .380's in the size/weight class similar to Kahr PM9 if those smaller (mousegun) .380's are too snappy for ya'... But LOTS of women like them!