A couple or so years ago, there was a fella here who made 100% hemp oil soap that his kids loved for the bubbles. I tried it and it does bubble prolifically. It also wears away super fast, but if you keep it around too long it will go rancid, so you'd have to make it in small batches to be used before it can develop DOS. But if you are planning to sell, then I wouldn't do a high percentage hemp oil soap. Only for home use where you can actually control how long it sits around the house. If you can't source an affordable hemp oil (it is rather expensive here), then I suggest a much milder recipe keeping the cleansing number much lower.
For kids, I would avoid a high cleansing number because it's so harsh on their tender skin, as it is on my own. Instead, I'd use additives to boost bubbles, like sugar and also egg yolks, because the egg yolks not only enhance bubbles, they can counteract some of the more harsh aspects of a cleansing oil such as CO or PKO or babbasu. That is based on my own personal experience.
Another factor for soap for kids if you wish to enhance their bathing enjoyment might be to make it more attractive to them with interesting molds (car shapes, for example) or felting the soap with fancy designs that your kids would enjoy. Felted soaps act as a method of increasing lather and bubbles via friction as they are being used.