From what I understand the exemptions to the Presidential proclamation which Trump introduced for 'essential workers' still applies to Airline crews. I.e. You can travel to the US on a Gen Dec ONLY without having to prove vaccination status.
How long this 'loophole' will remain is to be seen though.
Well worth checking the validity with crewing before you go though.
HTH.
(enjoy the kids when they're young! It's remarkably true when people say they grow up quickly!)