Yes, you can add them yourself via your profile. Please note that this feature is not available in all clubs. If you do not see this section in your profile menu, please contact your club's front desk so they can do it for you.

On this page, you will find “Add people to my family”

Fill in the form and click “Add a new person”.

the main benefit of linking a person to your family is that you will now have your invoices grouped together.