When you are using the dining plan you get a certain number of credits based on the number of days you are staying and the number of people on the plan. So if you are staying a week, and there are two of you in the room, you will get 7 x 2 =14 sit down meal choices as in a buffet breakfast or dinner. You'll get 14 counter service selections and 14 snack selections. It doesn't matter how you use them. You can use them all in one day if you want. So if your wife wants to sleep in and you want to eat a buffet breakfast you will be out one full service selection. Then she can use a counter service credit to eat at one of the parks or the counter service restaurant in your hotel. You will also find that the serving sizes are tremendous. Your wife will have lots to share with you at each and every meal. Don't forget snacks are not necessarily small. Snacks can be a gallon of milk or a dozen donuts bought in your hotel convenience store.
Have fun with it and you will NOT be hungry!!!!