Hi Alicia!
I highly recommend staying at Disney's
Polynesian Resort if transportation to the parks is your top priority. We absolutely love the Polynesian because the theming is beautiful, the restaurants are wonderful (hello 'Ohana!) and the transportation to the parks is amazing. You will be on the monorail line for the Magic Kingdom and this is the only resort that is within a short walking distance of the Epcot monorail. You can also take the express monorail back from Magic Kingdom to your resort, which will save you 10-30 minutes.
The rooms hold five guests, so you will need two rooms. You can request adjoining rooms so your family is near each other.
Since you will have the Disney Dining Plan you will really love the food at this resort. You can dine at '
Ohana, which has the best breakfast and dinner at anywhere in Walt Disney World (in my opinion) and you can have breakfast with Lilo and Stitch. Kona is also wonderful. You can also get a Dole Whip flavored ice cream at a self-serve machine at this resort, which is delish!
Magically,
Stacy