Hi, Stacey!
Families of five have quite a few options when planning a stay in WDW; let's take a look!
In the post
Rooms for 5 Guests or More, you'll see a great explanation of your options. The most economical of these is most likely Disney's All-Star Music Resort, which comes with a kitchenette (as does Disney's Art of Animation Resort.) Not only will these resorts save Guests $ on a reservation for 5, by ensuring that only one room will be needed, but you'll also save $ by being able to prepare light meals in your room, as needed.
When we travel to WDW, we eat breakfast in our room every day, with the exception of one character meal. We bring bread, peanut butter, jelly, cereal and pastries, then pick up milk, butter, etc., at the resort shop. We're saving money and everyone isn't grumpy waiting for the last person to wake up so that we can get something for our grumbly tummies. Works really well on both fronts!
There are Moderate and Deluxe Resorts which can accommodate families of five in one room, too, Stacey, but the price will vary at that point. For comparison, I suggest that you put together a package in one resort online, then do the same with another. This will let you know what's the best value for your family.
Send more questions as you research your resort options, Stacey; I love to help!