Howdy Kim!! What a fun question!!!
I have two favorites.
My 4 year old little boy highly encourages you to select
Disney's Beach Club Resort. Stormalong Bay is a beachside water park that offers something for all ages!! Our favorite part of Stormalong Bay is the sand-bottomed pool. It has "magic Disney sand" and we love it!!! There is a small beach area in the middle of the pool where kids (and parents) can enjoy some fun in the sun and build a sand castle or just dig in the sand.
You will find a life-sized shipwreck replica with a 230-foot-long waterslide or you can relax in an inner tube while you float down the lazy river.
There is also kiddie pool with a miniature waterslide. We have spent many many many hours enjoying Stormalong Bay.
My other suggestion is
Disney's Art of Animation Resort. Here, you will find the largest pool at Walt Disney World Resort. While that is fabulous, the thing that makes this pool so amazing is truly inspired! The pool features state-of-the-art underwater speakers. Can you find Nemo?
There is also an interactive water play area that your 1 and 2 year old would enjoy and there are 2 other pools that are themed to match the artistry of the hotel.
I know your kiddos will have an amazing time regardless of the hotel you choose.
Thanks so much for your question and please let me know if you need any further information as you plan your vacation. Have a magical day!