Most of the forum suspected as soon as she just happened to appear at the chateau in time to shoot that Romulan in the back.
True but that is only because we were led to believe that it was a huge secret and that the Zhat Vash have no qualms at killing to keep it hidden, so we had no reason to think she was there to kill him.
Laris made it out to be some huge secret that no one but a very select few is permitted to know, even the Zhaban was sceptical although he could be in the know and was just trying to deflect.
Then all of a sudden we find out that the Commodore told Jurati who is not what I would call a reliable confidant, the only reason it could force her to keep quiet is if it is a prime directive issue, to do with time travel or most likely her work with Maddox, even then its a bit of a stretch to go from sharing cookies to offing him the way she did with no hesitation whatsoever.
There was no real need to tell Jurati, the Commodore already knows where Soji is (with Narek) and all she has gained is Jurati's help in killing him which could have been achieved far more easily in other ways without exposing the secret, they could have sent in a kill team to wipe him out and any trace he was ever there.
Its almost like the Commodore wants Picard to be involved, did she send Rizzo in after Dahj knowing that she would make a mess, exactly what kind of game is the Commodore playing.
Does knowing the secret automatically make you Zhat Vash or whatever the Federation equivalent would be, is it literally the knowing that does it, it certainly would seem so based on Jurati's actions in the episode.