Kid stoker pedals
Nika,
As far as pedal and shoe options for young children, I can recommend the old type toe-clip pedals. I have attached a picture of the ones I am refering to. These pedals have a little adjustment in the clip length but the best part is the ridge in the back. This raised lip which was made for special cycling shoes fit great in the arches of kid tennis shoes. When the straps are tight, the shoe can not be pulled out. We have used these for over a year with my 3 year old with no problems. I had a pair off an old bike but you can buy them at Precision Tandems as well. I am sure we will use clipless when they are old enough but we still have a few years before that. Hopes this helps.
Aggie_grad