Shina you are talking pre-pr, when she lived with Pushky. After her abortion when she moved out and realized by giving up JW what she had given up, she wanted him back. No matter what, I doubt Bani's feelings would have been more imp than hers.
Actually i beg to differ. Remember that amazing scene where she takes ladoo to JW when she finds out of her di being pregnant(that was after/during PR), i remember that scene cuz i was very angry at her for speaking to him that way. And then right after that the divorce/alimony case started, so as far as pia was concerned it was because she was "told" that JB's baby was a result of superwoman being drugged and possibly the reason for the divorce.
At that point, if she knew the truth, even if her feelings mattered to her more, she would've told the truth to JW, and unintentionally strengthed the JB bond. and jigs/ranveer would've been paying for their deeds by now.
Shina