Hi @KajosUg
We're glad you're here. When you get a chance, please introduce yourself on this forum thread. I'd also encourage you to add a real picture as your avatar because it helps build community!
so you want to collect data about all children let's say there are 5 of them and then choose just one randomly but if there are children aged 10-14 they should be prioritized and only one of them should be selected?
Is that what you need or maybe I don't understand something?