The movie used seven decades of tricks to take away her powers so we never actually got to see her be super. Every 5 minutes another thing takes away her powers. Even in the final battle the climactic ending of the movie she's shot with a kryptonite arrow and has to fight at a handicap. It's just a piss poor movie.
The acting was great, the story concept was great, but the scene to scene plot was just abysmal.