For every maid who is abused by her employer, you may hear stories of employers who treated their maids with great kindness and fairness and yet had them rob them, cheat them, and yes even kill them.
However when it comes to this maid it appears to be a different case. The method in which she carried out the attack, that too obviously aware of the harsh penalties, certainly suggests an act of vengeance. Now was this due to abuse or some other reason will be speculation until the facts come out.. which again might not happen!
That said when it comes to maids and employers even the most bizarre,out of whack things can happen.Like the maid who recently killed little Tala in Saudi has confessed to her crime saying her reason was that she found out her employers were planning on sending her home, and happy as she was in her life there, she didn't want to go back!