Looking for shared vault password

I set up a shared vault for my wife and I. It has been working wonderfully.

Now we just got the iOS upgrade and wanted to add the shared vault on our phones. But I don't remember the shared vault password.

I realize this is a silly oversight. But because of 1password, I've gotten into the habit of not bothering to remember any passwords other than my main password.

And because unlocking my primary vault opens all the shared vaults, it seemed logical that somewhere in my primary vault was stored the password for the shared vault.

But I can't find the password for the shared vault in my primary vault. Does it exist somewhere? Is there any way to find out what it was so I can add it to my phone?

BTW, if it isn't accessible inside your primary vault, that would be a nice feature to add. This is the only place where when I supply a password that 1Password doesn't ask me if I want to store it. It was an unexpected behavior.