Per doctors suggestion, Bani has to recieve more pain to come out of her shock.
If Jai plans to give her more pain by being close to Pia and possibly marry her, is that really going to work? I think finding out about Jai & Pia was what put her in this state, anything he does with Pia after that isn't going to affect her, she might even be expecting it.
Then again I have to remind myself that this is an indian soap and anything can happen.