I have never liked Pia but have always considered her a very interesting character. Her strengths and weaknesses have already been discussed b4 and Mahim has given a very convincing answer as to why she wants JW and not Pooch. So I will not go about answering those.
But only restrict myself to saying that it is her superwoman Amma ( and to some extent her jodu ka ghulam hubby JW) who is responsible for her state today. She would never have taken as much risks with her life as she did, unless she had rightly calculated that Amma would bail her out of every crisis.
What she could not have foreseen was that Amma would break her kasam when she would lay hands on her Munna. One miscalculation and she is on the floor now.
Rgds,
Pri