Tanveer is an opptunist, she has a well to do buisness but yet she does cheap and con jobs for Razia for money, she is backstabing her own so called best friend when she hides the proof of Razia crime in the doll factory, and she has no regrets about it.
if she is well of why does she need to be Razia hench man. so her motive is that she only loves to do evil deeds, she didnt think twice about her act of trying to kill Zoya. tanveer is only wanting to use Asad status for herself when she marries him to take revenge for the insults that Razia showered on her.
the fact that Tanveer knows that Zoya is Gaffur Siddique daughter, is only something she will when this discloser benifits her.
i have a feeling that Tanveer will go to jail when Asad finds out the truth about her and her attempts on Zoya's life. that is the time Tanveer will blackmail Razia about disclosing this secret to Zoya in order to get out of jail.
tanveer is not going to turn positive.