Hello, Jill!
Your plan for a resort that has a great pool but is close to Magic Kingdom Park is a great one!
If you haven't yet stayed at
Disney's Polynesian Resort, check out their webpage. There, you'll find out about both Moana Mickey's Arcade as well as Nanea Volcano Pool, and its 40-foot high volcano and 142-foot tubular waterslide. We loved the ambiance surrounding the pool area, too, AND the fact that it's only a quick monorail ride from Magic Kingdom Park.
If you don't mind heading a little further, but still close, to Magic Kingdom,
check out Disney's Wilderness Lodge, which boasts Fire Rock Geyser, Silver Creek Springs pool (with a slide) and Buttons and & Bells Arcade. What's also unique about this property is Chip'n Dale's Campfire Sing-a-long
and that you can get to Magic Kingdom Park via bus as well
boat.
Finally, if you're willing to step a bit further away from Magic Kingdom in order to have access to a really spectacular pool area, then
consider Disney's Beach Club Resort. This resort's "water wonderland," Stormalong Bay, features waterfalls, a lazy river as well as a waterslide AND is within easy walking to distance to both Epcot and Disney's Hollywood Studios. Of course, Lafferty Place Arcade will keep them busy, too!
I hope these suggestions help you find that perfect resort for your second magical visit to Walt Disney World! Please send any additional questions you may have as you plan your journey; I'd love to help!