At the risk of totally hijacking your thread (sorry), I'm wondering when/how you all introduced your kids to chess? DD3 keeps asking me to teach her, but I can't imagine that she'd have the patience yet.
no5no5, there's a board game that my two DSs (at 3 or 4) enjoyed and it was a good introduction to chess. It's called No Stress Chess. Around here, it's always at Barnes and Noble, and I've seen it in various toy departments. It is basically chess with playing cards. You set up the chess board as usual, and draw a card from the deck. The card tells you which piece you must move. If I recall correctly, you can choose from moving what's on your card, or what's on the last card your opponent picked.
It has a somewhat different strategy than chess -- aggressive moves generally fare better in No Stress Chess. It simplified things enough, though, when DSs were just learning, so that they didn't have to review every single piece on the board to determine their next move. With the element of chance, it also levels the playing field somewhat when kids who are in their early learning stages are playing with an adult. It results in much shorter games than an actual chess game as well.
I hope this helps.