I haven't seen any reported cases of children who died from the covid vaccine aged 12+. I did have a google. There were some cases in very small children who have been vaccinated in other countries where deaths followed vaccination (I think all under 5) but they haven't determined whether the vaccines played a part yet.
There are thousands of children worldwide who've died of covid. data.unicef.org/topic/child-survival/covid-19/
I'm not pro vaccine to the point of abandoning reason, there is clearly a very small risk of a fatal outcome for some adults with the AZ vaccine, this is now clear (I was aware of this risk when I had my AZ vaccine and decided that the risk of covid was higher to me). However, they're clearly monitoring the vaccines closely (they've also discovered the myocarditis link to the Pfizer) and following up on any adverse reported reactions.
I'd much, much rather we had mask mandates and kept covid levels lower, so it wouldn't matter as much whether people were vaccinated or not. But we're letting covid run out of control (viral dose does matter!) so the vaccines are the only thing people can realistically do to help themselves or protect their family, particularly with kids in school.
I think it is a choice that people should have, there should be clear information about the risks and unknown (as there are with ALL vaccines) and then people should be able to make that choice.
Every time I have a flu vaccination I have to read all about the risk of an anaphylactic reaction. Then give my consent. I don't think the covid vaccine is any different. It's a choice.