Unable share Apple Card with family members

Do you meet all of the requirements in the "What you need" section of Set up Apple Card Family and add a co-owner and participants - Apple Support ?

If so, what is happening when you try to use the remaining instructions in that document?

Not the OP but I have the same problem. I am the cardholder.

Both phones on 14.6 live version not beta.

Under “Choose Person” my wife is listed as “unavailable for sharing”. When I tap the three dots and invite it sends an authentication code to wife’s phone but then says “<wife’s name>” is already a part of your family sharing” or something like that on my phone. Can’t get past that.

Is your iPhone updated to iOS 14.6 which was released today? That is a requirement.