My vote is for chickenpox!
COVID weird rash scenario involves your DD being positive for 15 days before having symptoms. Very surprising. PLUS two ‘biologically unrelated’ children both having the chicken pox rash as a response to covid. Also surprising.
Where as the chicken pox theory only involves one surprising thing- that the son got covid and chicken pox at the same time. Of course for all we know, brewing chicken pox might have brought his immune system down.
I understand the NEED TO KNOW! My brain does that, if your brain does that too, it could be what makes virology interesting to you! I do have to temper my NEED TO KNOW or it drives me mad. I find asking myself if it is possible to know the answer with the information available, and if it’s not, I find it a little easier to live with the uncertainty.
Having said that, it will be interesting to see if the spots arrive in waves like chicken pox.
One last thing, and I hate to add to the unknowns, but if it was my child I might want to touch base with a Dr to see if Mis-c needed to be ruled out. As she has got a temp and rash a few weeks after covid.
But chicken pox does make sense.