If one person puts their charge card on the room key it is possible to have the charges sorted out at the end of the stay and each family can pay their bill at the desk. Each key has a number that can be separated out for this purpose. We have done it several times. I put the charge on my card and then the last night or early morning of check out day the other person goes to the desk and asks to have their charges totaled and pays that portion of the bill with their charge card or cash. We haven't done this in two years so be sure to check with the CM at check in that this can still be an option. If this won't work just have everyone use their own CC at the parks etc. n