if someone gains access to one of my devices and they get the PW is all lost?

@Henry_Barnett

Just to clarify a couple of things here.

But as you say, once the Mac is open then so is 1Password and the 1P vault.

1Password unlocks independently from the user account in macOS. Just because a user is logged in to their Mac, it doesn't mean 1Password is unlocked too. I'd strongly recommend allowing Touch ID or an Apple Watch to unlock 1Password:

• Use Touch ID to unlock 1Password on your Mac
• Use your Apple Watch to unlock 1Password on your Mac*

*Supported Mac models only – please see the list.

Similarly, I'd suggest making sure that your auto-lock settings are as secure as can be tolerated, so that 1Password locks automatically:

• How to set 1Password to lock automatically

Now I must persuade my wife to change her Mac login!

Your wife's Mac login password will only give access to the Mac itself, its settings, and so on. It's not the same as her 1Password account password which would unlock 1Password (and nor should it be!).

As such, if the Mac login password is weaker, it doesn't pose a threat to what's stored in 1Password.

Hope that helps. If I've misunderstood what you meant, I'm sorry for the confusion. I'll be happy to help if you need anything.