Diana is extremely powerful and has been trained by the greatest Amazon warriors. We see she is clearly fast enough to move and deflect bullets with her bracelets, which makes sense. After all, she's Wonder Woman. Director Patty Jenkins, however, explained the big screen Wonder Woman is "not bulletproof but she's not easily killed." If she ever is shot, she "heals very quickly," but she can be killed. For the sake of reference, it sounds like a more powerful take on how Captain America's abilities are portrayed in the Marvel Cinematic Universe. Knowing that, there's one scene in Wonder Woman that arguably pushes things too far.
When Wonder Woman and her team head to the front, she heroically heads into No Man's Land to draw the fire of enemy forces. It's one of the film's most inspiring, action-packed, and simply awesome scenes. But, if Wonder Woman isn't bulletproof, how exactly did she manage to avoid literally every bullet? You had multiple machine guns and dozens of soldiers unloading on Diana, who is standing right in the middle of open space. Yes, her shield absorbs the brunt of the bullets, and she's obviously capable of deflecting a few with her wrist bands, but her legs were almost completely exposed as she approached the enemy trench. So not one bullet managed to make contact? That's extremely lucky, to put it mildly.