"Go Read" As i suspected, you aren't even able to reconcile what you just said above. That's how Sciencey you are.
So let's take a look at the data. The most recent Moderna trial included 2,500 children aged 6 months to 23 months and 4,200 children aged 2 to 6 years. Keep in mind the original adult trial for Moderna only included about 40,000 people. How can this in any manner be classified as a sample size that is too small.
So tell us how many participants were enrolled for part 3 of the trial. By the way 380 patients in part 1 and 4016 patients in part 2 is certainly a sufficient number of participants.
I'm sorry, you'll have to research your own questions. But the original tweet stands as true, unfortunately.