The infection fatality rate for the under 70s with no co-morbidities is 0.05%. That's one death in every two thousand people aged under 70 who catch it.
For children (under 19) it will be much much lower - one calculation is 0.0003%. That's three deaths in a million under 19s who catch it.
So no, OP, I'm not frightened that my children will die of coronavirus or be seriously ill with it, and nor should you be OP.
I am however very worried about the effect of lockdown on their education, social development, qualifications, and mental health; and my ability to pay my mortgage and supply a home for them when the financial reckoning comes, with huge redundancies, higher tax rates, higher interest rates, huge cut backs in public spending, etc. That's the threat to our children, not a virus which barely has any discernable effect on them at all.
(My eldest has actually had it: he just coughed a couple of times for day. That was it. I made him a Lemsip but he didn't even bother to drink it.)