Deena,
If you liked the S&W 3906, then almost any of the older S&W 39-series single stacks should work for you. The original 39-2 (shown below) is more of a "service pistol" with a 4-inch barrel, 8+1 capacity and moderately light.
The "Ladysmith" and similar variants, like this 3914NL are compact carry versions of the 39-series.
Other compact, single-stacks you can evaluate:
- Kahr K-9, PM-9
- Springfield Armory EMP-9 (Expensive, scaled down 1911 to fit the 9mm)
- Ruger LC9
- Kel-Tec PF-9
- Taurus 709 Slim
I'll offer one other choice for you to try because it's a single-stack pistol and the trigger might be easier to reach -- a 9mm 1911 pistol. I'm often surprised that some women with "small hands" seem to find the 1911 suitable.
Colt's 9mm Combat Commander
Since you are currently using a Marlin .357 lever rifle for home defense, one of my questions is if you have attempted to find a .38/.357 revolver that fits your hand to accompany the rifle?