Hi there, Jennifer!
Each of the Parks at Walt Disney World offers a nicely-appointed
Baby Care Center, and each center does feature a microwave in its list of amenities.
Not only can you resat, nurse, feed, and change your child in these centers, but you can also stock up on any baby items you might need to replenish, including diapers, wipes, baby sunblock, formula, and more.
The Baby Care Center in Magic Kingdom is located near First Aid by the Crystal Palace Restaurant. In Epcot, you'll find the Baby Care Center in the Odyssey Center near Test Track. Disney's Hollywood Studios offers Guests a Baby Care Center inside of Guest Relations just inside the Park, and in Disney's Animal Kingdom, you'll find the Baby Care Center located to the left of the Tree of Life, just before the bridge to Africa.
Disney does its best to make sure all of its Guests - including its youngest! - are happy and comfortable, and its Baby Care Centers allow grownups to relax at the same time.
Have a wonderful trip!
See you later, celebrator,
-Deborah B.