What do you give the spawn of your brother's geektastic best friend? It's important to start small terrors off right in the world, you know...teach them to appreciate the important things in life.
So you should give them plush multi-sided dice, naturally.
A d4, d8, and d10, handsewn out of felt. I used patterns from
this site as a guide--they're intended for making paper dice, but it was easy to adapt. And it only took six hours of watching Leverage to make them!