Hi Rina!
Congratulations on your upcoming Walt Disney World vacation and your new little on on the way!
Disney's Animal Kingdom Lodge is a beautiful, serene resort choice most definitely. Knowing that you have concerns about distance to and from Magic Kingdom and needing naps midday, it may not be your best choice for this particular visit.
Disney's Contemporary Resort may be an excellent choice to fit your needs since not only is it close to Magic Kingdom, but also connected by monorail to the Transportation & Ticket Center from which you can connect via monorail to Epcot.
Another fantastic option to consider would be
Disney's Wilderness Lodge. It may offer you the perfect balance of the quiet, serenity you'd find at Animal Kingdom Lodge, combined with proximity to Magic Kingdom. It's tucked just around the corner from the Contemporary, along the shore of Bay Lake. The added novelty of frequent and relaxing boat service to Magic Kingdom, as well as available Bunk Bed Rooms, makes it a big hit with many young families.
I think you'll really love Disney's Animal Kingdom Lodge, perhaps when your family is returning on one of your
next Walt Disney World vacations and when popping back for naps isn't a necessity for you. Choosing to be at a resort close to Magic Kingdom, while your family is still very young, will make your vacation all the more enjoyable!
Having stayed at all three resorts with my own family, with my children at varying ages and stages, I'd be happy to answer any further questions you may have to assist in your decision making. Please feel free to write me back any time you wish Rina!
Wishing you a simply Magical time as you plan your Walt Disney World vacation!
Kirsten