Jaime,
When I have travel plans that get me to my resort after the lunch hour on my arrival day, I like to do a non-park activity. I don't do this just to save the money of buying another park ticket, but also to explore some of the other cool stuff that is on Walt Disney World property. Here are my top choices of things to do;
Swim and Dine: We like to take an extended afternoon swim at the resort, followed by a fun character meal or dinner show (or other similarly fun dining experience like the
Whispering Canyon Cafe) to kick off the vacation in a fun style.
Do the Town: Downtown Disney has so much to offer, but we often can't seem to fit it into our schedule. So an afternoon of shopping, paired with an early dinner, means fun for the family. Plus we can get back to the hotel for an early bedtime that allows us to be fresh and ready for our first full day.
Take a Walk: A
BoardWalk, that is. It makes for a quieter evening than Downtown Disney, but that can be good, especially with younger kids like you have. Get some ice cream before you go, and again you can go to bed early to prepare for your first big day!
Write me back if you want to explore details on any of these ideas.
Have a magical vacation!