Hello! @sharon
Welcome to the LastPass Community.
Great question, and yes you will be able to send an invitation and have your partner join your LastPass families plan, none of the saved passwords will be affected in any of the accounts, Also you will be able to create shared folders and share information between users in bulk in set of going one by one.
Please let me know if you need additional help.
Greetings!
Verlaine | Customer Care