Hi Welcome to Cruise-Chat. I went on the Explorer last summer. There were TONS of kids, of all ages. I can not imagine, there would not be at least a few kids in her age group in January. Are you thinking about March for spring break? I personally would book whatever is cheapest/more convenient for you. She will have a blast with a few kids, or a ton of kids. My husband and I enjoyed the Explorer very much. We never felt it was overridden by kids. The over 16 yr solarium is great, with 2 jacuzzis and a nice pool. Enjoy and welcome. Lil' Lori
P.S. DON'T miss the first night parade down the promenade. They have crewmembers dressed up in awesome costumes, of sea creatures and such. It is way cool.