Hi Kathleen,
Thanks for stopping by the Disney Parks Moms Panel with your question. I recommend two options for a reasonable, tasty breakfast at Downtown Disney Marketplace.
Earl of Sandwich has a variety of (can you guess?) breakfast sandwiches and also has yogurt parfaits, oatmeal, and muffins available.
For more variety, you might want to try
Wolfgang Puck Express at the Marketplace. This is a quick service location and has breakfast pizza, omelets, and a variety of breakfast dishes. (There is also an Express at Wolfgang Puck Grand Cafe, but it does not serve breakfast.)
Please let me know if you have any other questions!
Wishing you a magical vacation,
Amy H.