Probably letting out too much information but my oldest Girl has a daughter now just on three. I hauled her into the Yamaha shop the other day just to have a look at ( and a sit on ) the bikes. She was only allowed to sit on the twostrokes. I think there was only one twostroke there as they seem to be all fourstrokes now? She's very keen, but mum said no!! I can't see a problem. I'll try again when she's say three and a half.