That's an interesting point I need to think about. I do wonder how the deaths would compare to the number of trips taken, because children in the US take significantly fewer trips by bike than children in the Netherlands. Given that pedestrian deaths were at a 40 year high[1] in the US last year, I wonder if the relatively smaller number of children killed is simply a reflection of the low number of children walking.
I can say though that the few times I've ridden on the road with my children were the most stressful of my life, I have never done it since, and it made me completely understand why I no longer see any other children or parents doing it.
[1] https://www.vox.com/23784549/pedestrian-deaths-traffic-safet...