I agree with Kubare.
Well, Bani told Jigs about Anu and Jigs did not even know about her daughter's habits of drinking and coming late. She talked all dirty words for Bani and her sisters. The mother inside her felt Bani may be right and later, she gave preference to kicking Bani out of the house, than discussing with her daughter.
When the pundit was telling about Anu's future, Anu's face looked worried which Jigs did not notice.
Anu did not go to Bani with her problems, but accidentally she met Bani at the hospital and had to disclose the problem to her. Bani just did the right thing that, she did not let unwed mother's name to be recorded, and she gave her name bcos she is married. Before she even reached the house, the Dr. broke the privacy rules and gave the news to the entire family and the family never gave her any chance and abused her with derogating words.
She also told one sentence when Jai was hurting her after hearing the news. "You have always searched both good and bad in me. I know, if you can behave good with me, you can also behave bad with me". Means, she is not sure how he will take the news and how he will react, if she says that she volunteered to accept the blame.
If he lost his balance and shouted at Anu in the party, Anu's izzat and Walia family izzat will be lost. If he did not believe her, he may just give a different meaning to it, and throw her out of the house right away like he did earlier. So, unsure of the outcome, she decided to take the blame and if the divorce has to happen today instead of few more days later, why not help the girl, whom she treated as her sister.
Jigs may say anything that who is she to interfere. But, if you look at the situation Anu is in, she would have been humiliated and insulted by the society and would have probably carried the stigma for ever. Probably, Rohit (her BF) would have used the opportunity to give her a slip by claiming that he do not know who the father of the child is and that he is just targetted. Still, it is not yet reached the stage where his parents are due to meet her parents, and who knows, what is their expectation or reaction.
Bani did not take Anu with her to discuss the abortion with the Dr., means she still has covered her in the public. But, if it was an abortion case, probably, she would have discussed it with somebody other than Anu - we do not know. But, everything happened so fast, that nobody realized the effect till it was done.