As for defensive use, if that's all the gun you will carry, then carry a .22. I know I feel better knowing my daughter has that .22 than nothing at all. I don't think your average thief is going to gauge the barrel hole accurately in a split second and decide "Can I survive a hole that size?" His thought will be more like "Ooops! Gun!"
Load it with CCI Stingers, as CCI is the most reliable brand in .22LR ammunition.
If you want to consider a mild upgrade, look at the new polymer-frame revolvers from Ruger and others, in .22 magnum. It's only a little hotter, still almost no recoil, but LOTS more noise and flash. If you don't hit the BG, he will be blind and deaf for a few minutes
![Shocked :shock:](./images/smilies/icon_eek.gif)
The Bersa .32 ACP is also worth a look. I have not shot one, but .32 is relatively low recoil, and the Bersas are well regarded. Plus they fit the hand well. My wife has a Beretta Tomcat with laser grips, in .32 ACP. it's also worth a look.
Spend a few hours at a range with one of the local people.
Good luck with your shopping