Hi @Vanessa267,
It is against the company's rules to book for someone else. If you let them in , you won't be protected by airbnb if anything happens to your place.
This reservation should be cancelled. I recommend strongly that you do not do it. Call the company and have them do the cancelling. They will when the situation is against their rules, and they levy significant penalties to hosts who cancel.
You would be forgiven the penalties as this is against the rules, but it would be a bit of a headache for you, and why not avoid that?
Last, my symapathies that this happened with your first booking. This does happen, but most guests are totally legit and great. Don't be dismayed..