She can declare the ball unplayable, but the only way to not hit from the bunker is to take a stroke and distance penalty and hit her ball from the previous spot. You cannot use the other unplayable options to drop outside the bunker.
Ball Unplayable in a Hazard
Q. May a player declare a ball in a hazard unplayable?
A. The answer depends on the type of hazard the ball is in. If the ball is in a water hazard, the player may not declare the ball unplayable. He may play the ball as it lies, or proceed under the water hazard Rule (Rule 26-1). If the unplayable ball lies in a bunker, the player may proceed under any of the options listed in Rule 28. However, if he elects option b or c, the ball must be dropped in the bunker.