Oh, Flor! I am so happy that you stopped by with this great question.
You see, just a couple of weeks ago I planned a last-minute vacation for my crew, and there were simply no
Disney Park Pass system reservations for our desired theme park on the date that we wished to visit.
What we did, and what I recommend you do, is to
keep checking! People change plans all the time, and as someone cancels a reservation, you may be able to snag it for you and your little ones!
If that doesn't work, I suggest that you purchase a theme park ticket with the
Park Hopper Option. This will allow you to reserve an available theme park and hop over to the Magic Kingdom after 2:00, as long as the park has not reached capacity. Please note that with the Park Hopper Option, you must enter the theme park that you have a reservation for, before moving onto your second park.
With little ones your age, I would recommend starting out at Disney's Animal Kingdom before heading over for a magical experience at the Magic Kingdom. If your little ones are huge Frozen fans, like my 4-year-old, you may want to start out at EPCOT instead to experience
Frozen Ever After instead.
Best of luck with your Disney Park Pass system reservation, Flor!
Sarah B.