There was a lot of ADR, computer manipulation and (in some places) outright dubbing of her voice. As I said, she's admited herself that she's not up to snuff and she worked with the director for key scenes that they felt couldn't afford to be sub-par. It wasn't a complete dubbing, but there was a lot of work done.
Life is like a roller coaster. It has its ups and downs, but if you sit back and relax you get a heck of a ride.