Hi Sue Anne,
Caribbean Beach Resort holds a special place in my heart as it is where I honeymooned with my husband there 20 years ago.
I can think of a few good places for a photo in Magic Kingdom and Epcot. Hopefully, one will work for you.
In Magic Kingdom, there are the sleds behind
Ye Olde Christmas Shoppe in Liberty Square. I took our Christmas photos here one year. Another option of course is Main Street or in front of your favorite ride. You can then have a cute caption such as "Wishing you the Wildest Christmas" if you were in front of Big Thunder Mountain Railroad.
Another cute area is in the town square area in front of
Gaston's Tavern in Fantasyland. I love the feel of this area and you might capture the Beast's Castle behind you.
For Epcot, I love any of the countries of World Showcase to grab a shot. Perhaps one that represents your family's heritage. United Kingdom has the phone booths and a beautiful garden. The steps of the Japanese pagoda's is fun or the trains in Germany or the Eiffel Tower in France work as well.
I also like the backdrop of the fountains in Future World or the decorations that line the walk way between Future World and World Showcase.
Wishing you a magical vacation!
Beth