There are a ton of point and shoots that fit the bill as to being light, inexpensive, and taking good pictures. Olympus makes one that is waterproof (took it scuba diving actually in Jamaica) and I'm sure there are others out now. Somebody else makes one with an 18x or 20x optical zoom which comes in handy out in the field. You want all the optical zoom you can afford, digital zoom does nothing but blow the pixels up, making the picture grainy.
I used to carry a point and shoot in the field, but missed a lot of shots due to the camera booting up and the game being gone by the time it was focused and ready for a shot.
Then I bought my wife a Nikon D40 DSLR. The D40 is getting quite a bit of age on it now, but still works great out in the pheasant fields. Yeah, it is bigger than a P&S, but I just hang it by the neck strap and it doesn't seem to interfere. With a DSLR you get the benefit of switching lenses depending on if you want to reach out and take some distance pics, or be inside taking family gathering pics. Boot-up is nearly instant, so a flick of the thumb switch and pictures are taken nearly instantly. The DSLR lens focuses a lot faster than the P&S's I've been around as well.
The problem with an old DSLR like the D40 is then your wife gets into taking pictures, and the next thing you know she has dropped $1500 on a new camera body, and then lens start adding up as well. She has taken enough family/senior pics to pay for all her extras, so I guess it is ok.......