Stop unwanted Keychain sync between users Every now &amp; then my mother has a login to some service on her iPad autofill with a login of mine. Initially I thought it was a few Keychain entries inherited as a result of a clumsy first handover of an old iPhone of mine to her (iPhone 3Gs in 2010). However looking at the passwords on Mum's iPad shows that passwords of mine are still syncing to her iPad, or have been until inside the last year, because there are accounts of mine that are less than a year old.
Things I've done...

Manually deleted a bunch of passwords of mine from Mum's iPad (while hoping that deleting won't sync back to my devices).
Checked Accounts on Mum's iPad for accounts of mine &amp; found none.
Checked the Keychain on my Mac for passwords of Mum's &amp; can't find any (making me think whatever is happening is one way).
Checked for devices associated with my Apple ID, where I found Mum's iPhone 7, which used to be mine (Mum inherits my old iPhones when I upgrade but bought her iPad for herself). I've removed that iPhone from devices associated with my Apple ID.

What other steps can &amp;/or should I take to stop accounts of mine syncing to Mum's iPad?
If this was caused by Mum's iPhone still being associated with my Apple ID, can I expect passwords of mine to disappear from Mum's iPad now that I have removed it?
Most probably you both are using the same apple id. Try creating another one for your mom. They will no longer sync.