Welcome aboard, Carolyn!
The Easter cruise is sure to be a wonderful one, and I'm thrilled you are taking what sounds like a multi-generational family adventure!
One thing you can be sure of is that there will be no shortage of photo opportunities onboard the Dream. Most evenings you'll find that there are scheduled photography sessions going on in the Atrium (in addition to all the character photo spots). These might have a white background, themed background, or be on the grand staircase. No need to schedule anything ahead of time. Just check your Personal Navigator for the days and times of the sessions, and walk right up. Your Key to the World card will be used to scan for each photograph so that they know who you are.
Each day in
Shutters, the onboard Photography viewing spot, you can find your family's photos from that day (and days prior). Browse what you'd like and purchase however many you might want. A big group shot is a great idea. Since I'm our family's official photographer, I tend to have a bunch of photos of everyone but me. So, on the Disney ships, we're always sure to take advantage of the scheduled photo sessions so our entire family can be together in the photos.
Happy planning, Carolyn, and please let me know if I can help with anything else as you get ready for your cruise!