Hi Hayley Joan!
Thanks for bringing your question to the Disney Parks Moms Panel. I often travel to Walt Disney World Resort with girlfriends and I'm so thankful that we can all put our own information in to prevent having to "split the bill" at the end of our stay!
When your sister completes her
online check-in, she will only be able to provide one credit card at that time. However, when they physically arrive at
Disney's All-Star Sports Resort, let a friendly Cast Member know that they'd like to add additional cards to your room. They'll assign the appropriate MagicBands to each card at that time and they'll be good to go! Your son will also need to pick a pin for his MagicBand, which will be used much like a debit pin, to authorize purchases on his MagicBand.
I hope this helps in planning your sons visit to the
Most Magical Place on Earth! Please come back and let us know if you have any other questions before his visit.
-Lindsey