@Veronica588
Why is your being SuperHost relevant to your post?
You've been barely hosting 6 months, which does not suggest a great deal of experience.
And its notable that you have not used the option to edit no 'Parties or Events' under Booking Setting in House Rules.
Moreover, you evidently experienced a 3rd Party Booking violation. If you can prove the elder brother did not attend the premises, Airbnb may well delete the account holder and a issue a full refund for damages.