@Sarah2479 Hey Sarah 🙂
A lot of my guests who book forget to change the amount of guests who are coming. So it will show 1 guest, but there are really 2.
Since your listing says up to 10 people, I would assume whoever booked did not think it was an issue to have 9 guests total (maybe they missed changing the number of guests).
As for the extra charge, for this group of 9, if you didn't specify in your listing that there is an extra charge, then you can't ask them for more money. But you can add in your listing for the next group who books that you are charging an extra $10 or whatever amount you choose, per person. And I've only seen most hosts charge the extra person amount when it exceeds the number of guests the listing allows. Your listing allows 10 guests, so technically most hosts would only charge when there are more than 10 guests. Hope that makes sense 🙂