Extended family trip - linking kids in MDE

We are joining my BIL, SIL and niece who are vacation club members for a trip in April 2020 and trying to get MDE sorted out for the trip. BIL is taking the planning lead (so I get to take a back seat) - we’ve got my DH and I added so BIL can make plans for us in MDE but I can’t figure out how to make the kids available to him for planning? I also don’t see the vacation club accommodation reservation - should I?