Some things I noted.
They don't define "children" anywhere on the website. My guess is that they are including everyone up to 18, at least as a "child". That's a reasonable cutoff, but it includes a lot of persons that probably don't fit the picture that most folks immediately form when they hear the word "children". It would be nice to have some kind of breakdown to see what the actual ages are. My guess is that such a breakdown would show that the deaths are heavily weighted toward the upper limit.
They are careful to define what they mean by "defensive use", but their definition will result in pretty low numbers for reasons that are well explained by Gary Kleck in his survey. It's sort of unavoidable if you want to have data where you can pull up a specific incident and talk about it, but it does tend to give the impression that defensive uses are much less common than experts agree they really are.
Boiling large, complicated data sets down to very simple plots or charts can hide a lot of important information. For example, most people tend to form an immediate picture in their mind when someone talks about a murder victim. The picture is often pretty innacurate.
Here are the summary results of interesting study in one large city.
https://www.wbaltv.com/article/bpd-2019-murder-victim-suspect-analysis/30374201#
- Over 80% of murder victims had a criminal record.
- Almost 70% of murder victims had a previous drug-related arrest.
- Over 40% of murder victims had been previously arrested for some kind of firearm related crime.
- One in 6 or 7 had been shot before.
One more interesting data point. Almost exactly the same statistics applied to their killers.
So, we look at the plots and think. So many innocent people killed. Which, I suspect, is exactly the goal of the website. In reality (though I don't mean to downplay the tragedy or loss of life) it's really more about so many criminals killed by other criminals. Again, not saying that's a good thing, just that it's not exactly what most people are going to think when they look at the plots.