Welcome Aboard, Lee!
Wow, you'll be sailing away on the gorgeous
Disney Dream before you know it - I know you must be SO excited. Thanks for stopping in with your question!
I totally understand how your wife feels! I have a special blanket (A Disney Dream blanket, as a matter-of-fact) that I like to sleep with. I swear, I'm like Linus from Peanuts with this blanket! She's more than welcome to bring her own pillow with her. You can choose to put the pillow in your checked luggage, or carry it on, whatever is easiest for you. If you carry it on, just know that your stateroom may not be ready when you first board the ship. You might not want to have to lug a pillow around until you get in your stateroom, so just consider that when packing.
One thing I can say about the bedding on the Disney ships is that it's FABULOUS. To me, it's like sleeping on a cloud every night - and I'm not exaggerating! Your wife might just find a new favorite pillow, right there in your stateroom.
I hope you have a wonderful time on your first voyage with Captain Mickey! Happy sailing, and sweet dreams! - Diane W.