Ahoy, Regina!
Dealing with seasickness is something no cruiser wants to deal with. There's so much to see and do on a Disney Cruise, you don't want to be sidelined by being green in the gills!
Stateroom location can be a big help with motion sickness. You'll tend to feel less motion in staterooms located on lower floors, and toward the middle of the ship. Try to avoid an inside cabin - a view of the horizon can be really helpful when getting used to the movement of the ship!
If you're concerned about seasickness, you will probably want to explore your options before sailing. For our family, we've had success with Dramamine. I usually take one about 30 minutes before boarding the ship and then as needed as the ship is in motion. You really don't feel a lot of motion on the Disney ships, but sometimes it takes me a while to get my "sea legs". Sea bands are another option - they are tight-fitting bracelets that hit key pressure points on the wrist. They can be purchased at most pharmacies, and have no side effects from medication. Other guests choose time-released motion sickness patches (you'll need a prescription for those).
There's nothing I love more than visiting Disney's private island paradise,
Castaway Cay. Starboard-side cabins have the best view of the island when docked, since the ship is usually "backed in" at the port.
I hope this helps with your planning! Have a magical day! - Diane W.