My eldest is 4, and has been on at me to play soldiers with him.
It was my own fault really, but a while ago I had a battle between my Ogres and various dinosaurs and monsters. We rolled a few dice and measured a few things, and I managed to salvage my models before the abstraction of combat went over the line into being pounded by a plastic Tyrannosaur.
Since then he's played with my Imperial Guard - broken powersword - looked at my 6mm stuff - T34 has mysteriously disappeared - and keeps asking when am I going to play soldiers with him again.
In an effort to placate him, and also to encourage his interest - after all there are plenty worse things he could be doing than modelling, wargaming and reading about history - I bought him the 1/72nd Airfix Robin Hood and Sheriff of Nottingham figures. Ideally I would have liked to have bought the playset with Nottingham Castle, but a) I couldn't find it and b) have you seen the price of those playsets these days? It is absolutely scandalous. I my day.... ;)
The other day I really wanted to get on with some basing, but I was left in charge of childcare due to the missus having an opticians appointment. So I had the bright idea of breaking out the paints to let the kids have a go at painting the Airfix soldiers. I say kids because my 2 year old has to do everything his big brother does.
It was pleasantly successful. I got all the basing done. They were kept entertained for over an hour. I was particularly impressed with Maid Marion's gold and horse. In fact they took to painting lie natural born geeks, even insisting on eating biscuits between colours.
By the time the missus got back, we had moved onto painting woad designs on our arms.