Emily Ratajkowski has come a long way since her days starring in the music video for Robin Thicke's song "Blurred Lines." That video stirred up some controversy for something Ratajkowski and other women walking around bare breasted. Since then she has had a great acting career. If you don't have faith in her as an actress, check out the Netflix show 'Easy.' She has a role in one of the episodes that is quite impressive.
She definitely has the other-worldly look necessary for Wonder Woman, but her lack of experience acting must have kept her from the role. Sure, she's been in plenty and done a great job, but she's still not taken 100% seriously in the acting world. It might be seen as reckless to cast her in a movie with so much on the line.