We were on the 7/7/07 Med cruise with our boys that had just turned 10 and just turned 6. My ds6 was about the size of a 4 year old and we had an umbrella stroller that we used only in Rome when we did the Rome On Your Own excursion with lots of walking. In the other ports he walked everywhere and never complained once about walking, being too tired or being bored. I would definitely bring your daughter along. I thought DCL did a good job with age appropriate restrictions on certain excursions letting us know what would be good for our sons. They both talk about our cruise often and have brought in pictures and other souvenirs when their classes study Rome, Pompeii, etc. It amazes me everything that they remember about the trip and ds now 9 even won their class daily trivia a couple of times from facts he learned on our Rome and Pompeii excursions. We are going on the Baltic this summer when they will be turning 13 and 9 and can't wait.