How do I keep from sharing my passwords thru family sharing to my kids?

“Family Sharing” means DIFFERENT AppleIDs for each and every individual.

Do NOT use a “single/common” AppleID any more than you’d share a toothbrush.

If each individual has their own AppleID, passwords will not be seen.

Set up Family Sharing - Apple Support

Create an Apple ID for your child - Apple Support

Manage Family Sharing settings – Apple Support (AU)