My iCloud Keychain and passwords have started to appear on my mother-in-law's iPhone?
I have just bought a new iPhone and set it up last night. This morning I get a message from my Mother in Law telling me that all of my passwords have appeared in her Password and Keychain area. This happened a couple of years ago; I can’t link it to any specific event but at the time we deleted them and they didn’t update with any new passwords after that point. Fast forward to now and suddenly they have reappeared.
I have done a security check and I do not appear to be connected to her account in any way.
How can this happen and more
importantly, how do I stop it please??
[Re-Titled by Moderator]
iPhone 15 Pro Max