Hi, Jennifer! Staying at Port Orleans Riverside (a moderate resort) with a party of 5 can be a bit "cozy" but it isn't too bad! However, you do have some options.
One idea would be to change your reservation to a
Fort Wilderness Cabin. The cabins sleep up to 6 people and have a separate bedroom, living area, and full kitchen. This might offer you the extra space you are looking for.
Another option would be to book a Family Suite at the
All-Star Music Resort. The Family Suites sleep up to 6 people, have 2 bathrooms, and a kitchenette with microwave and refrigerator.
These are the 2 options that will give you some extra space and without breaking the bank. If you decide to change your reservation, I would call to have this done as soon as possible as rooms in June do book up quickly. Compare the resorts and price differences, and do what you think will work best for your family.
Whatever you decide, I hope your family has a great vacation!