Hi Rebecca,
What a special trip to Walt Disney World you are planning - a first trip and a birthday trip rolled into one! I also have a 12-year-old daughter, so let me share with you how we manage our days at Walt Disney World. Another great resource for this is the planning page for
Walt Disney World with older children.
All families and all children are different, so of course consider what you know about your daughter and her energy level. My family tends to find that early in our vacation, we are super excited and up really early and have more energy to be in a theme park all day long. If you are planning some longer days, I would suggest putting them early in the vacation.
My family rarely will spend a whole day in a theme park from morning
Extra Magic Hours until closing. We tend to like to head to a theme park early in the morning, and then by early to mid-afternoon we are ready to go back to our resort hotel for a pool break. When our daughter was younger, this was a nap break. But now we find that heading back to our resort, spending some time at the pool and then freshening up to head back into the theme parks makes us re-invigorated and ready to go.
I should say, we can also be at theme parks from park open to park closing, which we do sometimes when visiting with friends who are having their first trip to Walt Disney World. My daughter does have the energy to do this! If you think you will be in a theme park all day long, I suggest that you plan a late lunch at a table service restaurant. This will allow for a nice, recharging break with air conditioning and to refuel in the middle of the day.
I would love to help you plan more Rebecca; however, the space that I have to answer is limited. Please do let us know if you have any further questions!