Legal heirs

My mother purchased a property in 1975. My mother had 1 son and three daughters. My brother was nominated as he lived with her. My mother died in 1997 Intestate and my brother as the new nominee put his wife as nominee. My brother died in 2016 and we gave a NOC for selling the property to my brother’s wife. The property was sold in 2017 and the proceeds of the sale were deposited in REC ( capital bonds) and FDs with her consent that she would not touch the principal amount. This was necessary till the capital bonds matured by end of 2020. She had also given a notarized self declaration that she would neither use the principal amount nor withdraw any money from the bank from the current bank. The interest was exclusively used by her till date. Now she wants to withdraw the principal amount and deposit in a different bank. How can we stop this and claim our rightful share? We are told by our lawyer that she was not the owner of my mother's home and we have equal right as legal heirs and we can dissolve all the FD and share it amongst the 3 sisters and my brother’s wife. In 2016 she also sold my mother's jewelry along with her own. I was present during the sale and I had made an inventory list of the item name, weight and the amount received from the jeweller. What proof would I need to add my mother's jewelry to my mother's estate? I have the original purchase receipts all in my name. In 1997 I transferred to my brother a lot of FDs which was in my mother's name jointly with me. What documents do I need to claim this as part of my mother's estate?