Ahoy, Mary!
Welcome aboard, and thanks for visiting the Disney Parks Moms Panel!
I'm happy to hear you're proud members of the Disney Cruise Line Castaway Club! Repeat cruisers enjoy special extras and benefits, including advance booking for onboard amenities and Port Adventures and a dedicated Castaway Club phone number. While you're already aware that you have access to a separate, members-only line, you are more than welcome to stand with your parents in the regular line during check-in. I would certainly want to do the same if my folks joined us on a Disney Cruise!
I spoke with a representative from Disney Cruise Line and asked what to do in your situation. First, call DCL at (800)951-3532 and have them link the two reservations (make sure to have both reservation numbers on hand when you call). When you complete your online check-in, she suggested choosing a later Port Arrival time to avoid the larger crowds from 11:00-1:00pm. Guests who check in around 1pm will usually arrive to a less crowded terminal and will have open boarding immediately after checking in - no waiting for them to call your boarding group number! As you enter the terminal, there will be a Cast Member directing guests to the correct lines for check-in. Mention to them that you'd like to be with your parents during the check-in process. It's possible your parents will be able to join you in your line! (It never hurts to ask!)
Regardless of which line you choose for check-in, Disney Cruise Line does a wonderful job of moving guests through the check-in process quickly and efficiently! From the moment you arrive at the cruise terminal, you'll experience Disney Cruise Line's personalized customer service, which is a step above the rest!
I hope this helps! Wishing your family a most magical vacation on the gorgeous
Disney Fantasy! - Diane W.