On one hand, I agree with Andy that for hand-held low-available-light photography, no point-and-shoot beats a D-SLR. Your wife would most likely consider the Canon D-Rebel and the Nikon D70. Both come with optional kit lenses that are nicely wide angle. For many other tasks beyond your intended usage, the Nikon D70 trounces the Canon D-Rebel, but the Nikon kit is $1299 versus $999 (?) for the Canon kit.

If (and only if) you're willing to use a tripod for low-light photography, then the right answer is almost certainly a Canon Powershot G5 (or the older G3, if you can find one for less). These have high quality optics and excellent low noise with their ISO 50 setting, but beyond that, forget it. On a tripod, all you would have to do is explicitly disable the flash and the camera should figure everything else out. You can use the self-timer or the included IR remote control to minimize camera shake. The only downside to a G3 is that the lens cap has a habit of slipping off the lens. I'm told they fixed this with the G5, but if the camera's going to be banging around in a purse, this could be an issue for you. I'd probably recommend you investigate the wild and wonderful world of camera bags. Somewhere, somebody makes a bag with just exactly the right amount of space inside.