4 kids
Herb good question !
My advice
1 make sure said kid ,can place both feet on pegs (and not at a stretch)
2 sit them close to you so you can feel them relaxing IE dozzing off!
3 wear a buddy belt (I prefered my kids to put their hands in my jacket pockets.
4 Spend the same money if not more on their gear as you would on yours (TOP OF THE RANGE) correct fitting
5 dont be a hero, treat the ride out as if you were riding a brand new bike you had just collected.
6 finally do not frighten them !
I have took all 4 kids with me since they could touch the pegs!
No problems and one even rides a scooter to uni everyday !
JMHO
mav