Welcome aboard, Trisha!
The private cabanas on Family Beach at Castaway Cay are a hot item! They book up very quickly! Many families who are at first disappointed at not being able to book a private cabana arrive at Castaway Cay and quickly find that there was nothing to worry about. There are plenty of loungers, beach chairs, hammocks, umbrellas, and space for everyone without feeling crowded on Family Beach, even without a cabana. In fact, my family and I choose not to book a private cabana when we visit Castaway Cay because we enjoy exploring the island so much that we wouldn't end up spending too much time in the cabana anyway! So, please don't worry about not having a private cabana for your family. I promise that you're still in for so much fun and relaxation on
Disney's private island.
There are, as you mentioned, private cabanas at Serenity Bay as well, however, since this is in the Adult Exclusive area of the island, they are for guests age 18 and over only. If you really have your heart set on a private cabana, even if your little ones can't join you, go ahead and book it! Castaway Cay has a fabulous island Youth Club called Scuttle's Cove, where little sailors ages three to twelve can hang out with the same counselors from Oceaneer Club and Lab onboard for some wet and sandy fun and games. My kids adore playing and participating in the fun acticigies that go on all day at Scuttle's Cove, and meeting up with their friends from the ship there. I am sure your kiddos would have a blast there too!
But, keep in mind that Castaway Cay also offers lots of family fun like Pelican Plunge water slides, Spring-a-Leak splash park, oversized games at In Da Shade Games, character dance parties, a family whale dig and so much more - all included in the cost of your cruise!
You're in for a great day at Castaway Cay, with or without a private cabana, Trisha!
Have fun!
Marcy