But it's still no reason to panic, because I think Zoya isn't the one who's going to expose Tanveer. Looks to me like she's left it to destiny, to Allah in a sense. Which is why we will get to see Tanveer getting caught red-handed by Asad when Zoya is praying namaz - divine intervention so to say.
Basically I think this whole Tanveer track will come to a close by Tanveer herself, not by Zoya or even Razia exposing her. It'll be karma that comes get her in the end. So I think Zoya's thinking at the moment is this:

And I personally believe it'll be a really good way to end Tanveer's track (: