Managing personal Outlook.com account settings, security, and privacy
Keep in mind that these are user-to-user forums. Most of us no not work for Microsoft and no one here has access to any account other than their own. We're just trying to help each other.
What happens when you try to log into one of the accounts by visiting https://account.microsoft.com/? Does it allow you to try to log in without a password? What process did you use to create the accounts? Please describe it in detail. Typically, to add an account to Microsoft Family, one needs to start by creating the account at https://signup.live.com/, which will require creating a password for the account, then adding the newly-created account to the family group.