No, your sample does not "show" anything, as it is a tiny number. Neither are there "countless reports" on the danger of the Delta variant in children. More kids testing positive with a newer strain is exactly what you would expect when one becomes more prevalent. You have to look at actual outcomes.
Interestingly, you linked an article from the very hospital where I trained, and I can confirm that there has not been any significant increase in Pediatric morbidity or mortality. We have also not seen any indication locally that children are at increased risk from this, or any, variant to date.