Wife got deprived of Inharited Property by In Laws

1. After father in law's death, before our marriage, my wife has signed some document which she can not recall, it was about the PF and other money to come to my mother in law. Where she and both of her brother has given consent by the signature. 2. My wife has 2 brothers 3. Both my brother in law has maintained my mother in law so far 4. Now my in law's house is demolished to make a new flat. The property belong to my father in law by inheritance. My wife has 1/4th share of the property after the death of father in law. 5. My wife has not given any NOC to the promoter/ in laws so far. The construction is on way. 6. Agreement between Promoter & owners got registered by the promoter - where others have signed but my wifes name is not there 7. There was no WILL by my father in law Question 1: how can we get the legitimate share of the following three property 1. 1/4 th share of the flat under construction. 2. Can we get the share of the money that my "mother in Law" had from my father in law, after his death. She has no source of income. 3. How can we get the share of the ornament of mother in law. While dividing the ornaments the ornaments given to my wife will be taken into account or not. Regards