Immie,
Look for "Charter Arms." They make a series of revolvers that are copies of the Smith and Wessons made from aluminum and cheaper metasl, but they are mechanically wonderful guns at about 1/2 to 2/3 the price of a Smith and Wesson.
If used guns are fine with you, then its time to go pawn shopping.
I would suggest
Guns - Online Gun Auction - Guns for Sale at GunBroker.com as well, but you're going to have a harder time finding one that is willing to ship to California. The laws there are so messed up that even most Californians don't understand them, so those of us in the other 49 just exclude sales to CA resident in order to avoid the liability. $25 to $30 is the going rate for a background check in those instances (we have to mainain your transfer paperwork for 20 years, so $1, to $1.50/year for filing and storing it).
And I would not be too shy of the semi autos. They have more points of failure than a revolver, but for as little as you're going to use it, you are very unlikely to encounter any jams or failures.
The Ruger Tomcat....great little semi-auto. The KelTec mentioned earlier, I carry one too. Ruger LCP and Ruger LCR, can't go wrong with either. Also look at Taurus for ALL guns. They make good copies of all the popular guns including the Tomcat and the Smith and Wesson revolvers.
Your biggest problem literally is your State of residence. Your biggest advantage is (I assume) that "little old lady who wants/needs to protect herself." Pawnbrokers have hearts (some of us)...go to a pawn shop and play that card (the "I need some protection" card), then play the "is that the best you can do, because I really like THIS gun, but I don't have THAT MUCH money." They likely paid half or less of what they're asking on almost all used guns. Use your charm and they'll come off the price, still make a profit, and you'll get a better gun.
Good luck!