I am sorry she does desvire jail time for what she has done she took a life (yes she snapped and killed him but he is not around to defend himself, the correct course of action was to go to the police) Murder is never right and if we allow people to kill people and claim sexaully abuse / DV so they get no punishment there WILL be more murders.
No one on here would like if a male murderer was abused by his mum / wife 'snapped' and killed his abuser he would be in prison and if he did not get a lengthy sentence there would be outcry.
Being abused does not and should not give you a free pass to commit crimes especially one as bad as murder.