Hiya Lisa, welcome to planDisney!
Thank you for asking such an observant question about avatar options in
My Disney Experience. The character each individual chooses to attach to their My Disney Experience account
profile says a lot about their personality. I chose Belle because of her adventurous spirit. My husband chose Mr. Incredible because he's quite strong. I'm just now noticing one of my friends chose Rex, and I must ask her, "Why?" when I see her next weekend!
Though I heard a rumor about a Disney Prince Avatar convention happening this month in A Far Off Land, I cannot state with complete certainty the reason for his royal highnesses' absence on the current character selection list. I do know that these options change over time, so I encourage your sons to check back before their visit to see the most up-to-date list of characters. My tween is really hoping Stitch makes an appearance before our next trip.
If your sons and their girlfriends wish to express their status as a Disney couple, I recommend the Aladdin/Princess Jasmine, Donald Duck/Daisy Duck, or classic Mickey/Minnie profile pairings. If they really want to be overt about it, I highly recommend coordinated t-shirts for their park days. "We finish each other's..." and "...sandwiches" are favorites from my personal collection.
I hope your princes have a magical time visiting Walt Disney World Resort with their princesses, Lisa. As for you, I think the Mrs. Incredible avatar suits you.
Plan magic; planDisney.
Jennifer