Washington would definitely be an interesting choice for the character, and she already has experience in the world of superheroes.
(For instance, Jason Momoa refused to admit that he had been cast as Aquaman until after the DCEU made the news public).
We think that Washington herself hits the nail on the head, however when she says you have to get the right person for the role.
Washington voiced Princess Shuri in an animated Black Panther TV mini-series in 2010, and played Alicia Masters in Fantastic Four: Rise of the Silver Surfer in 2007, and in Fantastic Four in 2005.