I sent them a message to clarify, as we were hoping for a 10 night stay (if availability opens up), so it would make a big difference.
btw 2 years ago when we stayed (booked a year in advance so 3 years ago), I posted about the discrepancy and booked 2 adults and 1 child, but stayed with 2 kids, quoting the website...however now you can actually book the bv with 2 adults and 2 kids confirmed at booking, so this has now been updated.
I will update the thread when i get a response