Briana,
I have several cameras including the K10D, and while I'm not sure of how seriously you want to get involved in photos of your kids (they could range from snapshots to serious art; just because they're your kids doesn't mean they're going to be boring photos -- c.f. Sally Mann.) I say that because the Pentax is a little more serious camera: My K10 with three lenses (70, 43 and 21) cost about $2500 total. A new high quality zoom lens coming in May will cost several hundred more dollars. However, there's a wide range of older Pentax lenses that will work, and also some cheaper kit zooms, so you wouldn't have to pay that much. If you've looked at the camera, you'll know that it does not have live view on the back like most P&S; and for me, the start-up seems slow -- about 2 seconds from "on" to first shot. Quality is good, but not as good, say, as a Leica, but a Leica is a lot more expensive camera. As good as an equivalent Canon, though. You know that it's a 1.5 crop, so that the 35mm focal lengths have to be multiplied by 1.5x to get the K10 equivalents...70mm has the same field of view as at 105 on a FF 35mm. Unlike other inexpensive DSLR, it has full weather seals and in-camera image stabilization. The IS is important, because with a lens like the 43mm f1.9, with IS, you're getting down to shooting in Leica Noctilux range. It's a very nice camera.
However, if I were you, and with just your brief outline of your uses, I would be more tempted to go with a camera like a Canon G7 P&S. Michael Reichmann, the owner of this site, has posted a review of the camera, and occasionally will post a landscape shot taken with it. It is a VERY good P&S, in my estimation, will save you some money, will be a lot handier to carry around, and for all practical purposes, will get shots as good as the Pentax, as long as you don't start shooting serious art landscapes, etc. It does have live view. It will also make is possible to upgrade your technology several times over the next eighteen years, for a total cost that would be not much more than the one-time Pentax purchase.
But the K10 is a good camera. I bought it when I got pissed off because my M8 died, and Leica takes forever to do repairs. The images are not as good as an M8s, but they're quite good.
JC