1) It's not likely she came up with the lawsuit. It was probably pushed on her by a lawyer or else someone with a right wing agenda manipulated her into playing divide and conquer for them. 2) The big news she exposed, assassination squads deliberately killing people rather than catching them, has not really hit the global media yet.
Netanyahu condemns West Bank arson attack, calling it 'terror' (Haaretz)
from the article: Anat Kamm suing Haaretz for revealing her as paper’s source