Playing Minecraft together on pc in this scenario

I have Xbox pc game pass and a java Minecraft licence (somewhere) (and Minecraft for switch, though that is not that relevant)

I am giving my Minecraft obsessed kid an Xbox Ally for Xmas. I've set up my own account on it so he can play game pass games under the same subscription (though not the same game online at the same time afaik). He also has his own steam account set up on it, with my games shared via family sharing.

I want to be able to play Minecraft minecraft with him under this set up. Not sure how? I currently use realms to play x-platform switch/pc, but this is awkward and the switch performance is not great.