Children's kitsuke

I need help with children's kitsuke, mostly girls. I can't find much info and have been looking all over for almost a month. So far all I have is little girls' collar goes against the neck, fluffy obi becomes solid obi at 7, himo is sewn on and tucks are pre-made. The info I would love the most to have is sizing for zori/geta since I can't find anything on that (do children need to be iki and have it be smaller than the foot?)
Does anybody know any differences other than the collar thing?

Have you seen images from Toma-san website? Theese are instructions - text is strange font, most people can't read it, but pictures are very clear

For 3yo http://www4.ocn.ne.jp/~tomasan/753onna3.html
For 7yo http://www4.ocn.ne.jp/~tomasan/753onna7.html
Fancy musubi for 7yo http://www4.ocn.ne.jp/~tomasan/obi7.html

Tucks diagram http://www4.ocn.ne.jp/~tomasan/age.html

As for shoe sizing, I haven't read anything specific, I think the easiest way is to look at neatly dressed girls I browsed in "shichigosan" photos by google, and when it comes to zori, they are not always visible, but I think, that sizing is not that important. Some of girls have them too big, some to small (and they are all very neatly dressed, so I don't think it's a mistake). I guess there are a few fixed sizes (just like for adults - it's difficult to find something different than 23-24cm), so girls who grow faster have them shorter than their feet, and those more petite have them longer.