The film follows 16-year-old Moana Waialiki, a keen adventurer and voyager who has a rare and special connection with her namesake -- the ocean.
Cravalho is a native Hawaiian and is also part Puerto Rican and Irish. She is a student at Kamehameha School and enjoys singing. Like her animated character, Moana, she is an only child.
Asked how she felt about how the movie, an effectively herself, would be representing Pasifika cultures, she said: "It gives me a responsibility."
Her first public appearance included the showing of never-before-seen footage from the film, which media were not allowed to record.
The scenes included one of demigod Maui, who also features in the film and whose voice is played by former wrestler Dwayne "The Rock" Johnson. The scene shows Maui -- covered in tatau (Polynesian tattoos) -- springing to life with his weapon of choice: a large fish hook with the power to "pull down the sun and bring up islands".
Another more poignant scene shows Moana as a toddler and her first interaction with the ocean. Sitting on a beach, she spots a conch shell near the water and waddles towards it to pick it up.
All of a sudden water washes towards her feet -- the first time she feels the ocean -- and she lets out a squeal and runs back towards the beach, laughing.
Also at today's news conference were the film's directors, John Musker and Ron Clements, as well as the producer, Osnat Shurer. All three were a part of a Disney team which travelled to parts of the Pacific -- including Fiji, Samoa and New Zealand -- over the last few years as part of their research.
The trip included a visit to Auckland's annual Pasifika Festival last year, at Western Springs, where they got to experience first-hand each of the region's cultures, foods and music all in one place.
Musker acknowledged that their responsibility to uphold cultural integrity in the film was vital and they had invested a lot of time not only travelling to the Pacific, but also speaking to its peoples and experts in the field.
He said one theme that stood out to him during that research process was Pacific people's connection to the land and heritage.
"You've got to know your mountain - you've got to know who you are and that's part of what the story of ours is about. You don't know really who you are until you know where you came from."