When I first started traditional scrapbooking, my niece and nephew were often the focus of my pages. But that was back when I was just starting out and had to budget how much film I could get developed and how much paper and adhesives I could buy. With the addition of other nieces and nephews, technology changed and I went digital and now I have soooo many more photos of the younger family members. So no, I clearly do not make the same number of pages per kiddo in our family.
However, when each of the kids in our family graduates high school, I select my favorite 100 layouts that I have created about them, upload them to Shutterfly, and present them with their own scrapbook of their childhood as a present. The older kids were happy with what I created, and now the younger kids know that they'll get one when they graduate. So I'll hear things like "Hey, take this photo. It would be good for my scrapbook!" Ha!