In Mortal Kombat 9 (2011 version) for the PS3 and Xbox 360, each character has multiple fatalities that they can perform at the end of the match.
This is the list of fatalities, and the babality and stage fatality for Sonya Blade.
All of these moves can be unlocked and added to your moves list by performing them in either Arcade Mode or Versus Mode.
Looking for more finishing moves? Check out my complete fatality guides:
Fatalities and babalities for Mortal Kombat on Xbox 360
Fatalities and babalities for Mortal Kombat on PS3
Sonya Blade’s Fatalities & Finishing Moves
Xbox 360
Kut-Throat — Down, Back, Forward, Back, B while in sweeping distance
Scissor Split — Down, Down, Back, Forward, X in jumping distance
Babality — Down, Down, Forward, A in jumping distance
Stage Fatality — Back, Forward, Down, Y, distance depends on the stage
PS3
Kut-Throat — Down, Back, Forward, Back, Circle while in sweeping distance
Scissor Split — Down, Down, Back, Forward, Square in jumping distance
Babality — Down, Down, Forward, X in jumping distance
Stage Fatality — Back, Forward, Down, Triangle at close range