Further tinkering solved the problem, in 1password7 on the 2nd account laptop I had to fill out a form from a pulldown menu choice under Account or Vault that required entry of all the information in the emergency kit download (including the secret key). After that all is working.
Apologies for the imprecise report of how it was fixed, l was trying a variety of click steps and did not keep perfect track of what led to the resolution.
I am trying to set up a 2nd account for my wife using the family plan. I upgraded my account from v6 to v7 and my vault contents imported just fine. I setup a new 1password7 account on my wife's laptop using the invitation procedure. I established a new 1password7 master password for her that works fine to log on to the my.1password.com site under her account. However, the same master password fails to open the vault upon trying to open 1password7, either directly or using the safari extension.
1Password Version: 7.3.2
Extension Version: 7.3.2
OS Version: 10.14.6
Sync Type: Not Provided