Minecraft – How to tame a villager

You should go into survival mode, turn on keep inventory, go to the nether, and kill yourself. You should NOT sleep while you're lost, or else when you die, you will be sent back to where you've last slept.

If this doesn't work, you could try building another castle. If you don't want to do that, try to create a map and if you don't see your castle on the map, fly somewhere farther away from your portal. You should keep creating new maps and spiraling away from your spawnpoint. You can do this without using maps, too. Eventually you should find your castle.

You may have an easier time buying the Java Edition and creating an account there. Your question wasn't too clear on whether or not you two share a laptop or necessarily want to share an account, but in either case it's pretty simple to make an account for both of you here.

In this case you create a Mojang account and it's completely independent of a Microsoft account (as your comments mentioned you'd like to avoid).

This takes Microsoft out of the equation entirely but it doesn't allow for you to create a "child" account necessarily or create parental controls. But in this case you just set up an account and you're ready to roll.

Plus the Java edition has the added bonus of much more customization compared to the Windows edition (which charges for things you can get and do for free in the Java edition).