Going through the same frustration. Pandora needs to clarify this process
@crazywhitworth Sorry for the trouble you are having with your Premium Family plan.
I took a look at your account, and do see you've sent two invitations so far. This being said, it doesn't look like a Pandora account has been created yet for either of those users.
Each user you want to add to your plan will need to create their own Pandora account before they can accept your invitation.
Once their accounts are created and they successfully join your plan, they can then sign into Pandora using the email address associated with their new account.
I have created a ticket with our support team for you.
They will be contacting you privately via email to help look into this further, so please keep an eye out for their message.
Thanks for your patience in the meantime!