Hi there, Emma!
At a la carte restaurants - like
The Wave ... of American Flavors - you are more than welcome to come in and relax with a drink or an appetizer or dessert while your children use their remaining
Disney Dining Plan credits.
This same policy does not apply to buffet restaurants; while a la carte restaurants are open to this, you will not be able to visit a buffet on a "split check."
Please remember that you are still considered a party of four for reservation purposes, even though two of you will likely not be eating.
And when you arrive, let your Cast Member know that you will need two checks: one to reflect the expenditures on the Dining Plan, and one for any out-of-pocket costs.
You can make your reservations up to 18 days in advance by calling (407) WDW-DINE, or by visiting the
reservations center online.
See you later, celebrator,
-Deborah B.