I went in October while 22wks pregnant. It was still pretty hot, but it did rain a lot to help with that. I suggest bringing multiple pair of tennis shoes to rotate between, at the end of my trip my feet hurt from being in the same shoes the whole time. We have always toured commando, so getting up and doing breakfasts and then having later dinners and seeing all the nighttime shows got exhausting. I would suggest using a touring plan so that you aren't criss-crossing all over parks and plan your fast passes accordingly. Don't make one FP at Jungle Cruise, your next one Space Mountain, only to do Splash Mountain next. That's too much walking! Be sure to do things like the Country Bear Jamboree and Hall of Presidents even if you don't think your daughter will enjoy them, the air-conditioned break was certainly a necessity. I would also suggest if you don't go back to the hotel during the day, to make sure you do a sit-down lunch to give her a good long break from walking and the heat. Keep a water bottle on you and constantly fill it with water. Constantly remind her to drink, even if she doesn't feel thirsty. My hubby kept on me about the water, and it certainly helped me.