Hi Stephanie,
Donald's Safari Breakfast is a great way to start your day in Animal Kingdom! I'm assuming that with your 2 small children, you are planning to leave the park for a couple of hours during nap time, and you're looking to eat during that time. ESPN Club could be a little far away depending on which resort you're staying at. If you're at Yacht Club, Beach Club, Boardwalk or Swan & Dolphin, it's perfect; otherwise, I would recommend finding a restaurant closer to where you are staying. It will just make transportation easier.
Or, you might consider dining at Animal Kingdom. The Rainforest Cafe is always fun for little ones. If you want a quick service meal, Flame Tree Barbecue is delicious. Also, there is a new picnic in the park that you can order. Click
HERE to read what Disney Mom, Anna, has to say about this new dining option.
If you resubmit this question and include your resort information, I'd be happy to give you my suggestions for restaurants outside of the park.
Hope this helps. Have a magical vacation!