It is not directly helpful (or unhelpful) to your point or to the parent as data doesn't seem broken down in that way. However, in all these sorts of discussions it would be really great if things had context. So, for example (and sake of argument) if someone says 800 children per day were admitted, we had a comparison. Is it high, low? How about a rate per 100,000 comparison across other countries? Not asking for anyone to do this, merely attempting to articulate my point.
A bit of eyeball math shows 12 million people in UK under 16. Even if 800 a day was true...should I worry?
Hospitalised with Covid or due to Covid?
Is there a public source for those figures?
EDIT: the data at this link[0] doesn't seem to agree with your claim
[0] https://coronavirus.data.gov.uk/details/healthcare?areaType=...