Advanced join button

In a near future, I am going to re-design some team screens and their join button. The platform I am designing for is a sports platform for admins to create and administrate their teams and for their users to easily join.

The main team screens is a basic overview of the team information etc. And at the bottom of the screen, I am going to place a join button.

Now... The join button has several states since the platform supports multiple "Sub users" that the main profile can create (It basically profiles for children). The state that I'm really interested in, is when the main profile has joined the team and you want one of your kids to join the same team. How should the button work and look?

The states are:

  1. Join - When users want to join

  2. Pending - When the users have requested to join and are waiting for the team to accept them

  3. Joined - When a user already has joined (This is the interesting one with the kid joining too, scenario)

I'd like to ask you guys for some advice on how to design the button to handle all states, and more specifically how to handle the button state when the user wants to sign one of their kids up to a team they are already part of.

If you need any elaboration or clarification, let me know!