Sister, Sister (1994)

Season 3: Episode 10

The adults realize that the girls are missing and set out to find them. When Tia accidentally falls overboard, they realize that they have drifted out from the shore, but the water is still only 2 feet deep. They get back to shore, only to find that the adults have gone out to sea in search of them. The twins decide to head back and begin making Thanksgiving dinner, so their parents won't be so angry when they get home. When everyone is finally back at the condo, they begin to have that long awaited Thanksgiving dinner when a tsunami warning sounds, and they all duck for cover.