Hi Jessica!
I am so happy that you will be treating your family to their first Disney trip!!! As a Mama to three young boys, I completely understand the need to stick to a budget - who doesn't these days? We almost always eat our breakfast in our room, we save so much time and money this way.
For the most bang for your buck, I recommend eating at counter service restaurants for your lunches. If you check out
Allearsnet.com, you can preview all of the menus at the parks and resorts. Based on these prices, you can bet on spending around $35-$40 plus tax for 2 adults and three kids. Please keep in mind that Disney servings are usually pretty generous and the lighter eaters in your party may even want to share!
Most people don't realize that they can bring food and drink into the park, of course no alcohol please! Feel free to bring bottled water, snacks, even lunch if you would like. Have an amazing trip!
Much pixie dust,
Jackie S.