Entitlement of daughter excluded in partition deed

In my wife's grand father's property, my wife's mother and wife's brother registered it during 1994 after partition by a partition deed in their names only excluding my wife's (daughter's) name. My wife's brother died in 2011 and wife's mother died in July 2016. My wife's mother had allowed her daughter to build a house on the ground floor with the understanding that my wife's brother has to build the second floor. My wife already built the first floor during 1994 itself but my wife's brother did not build the second floor. My wife's mother wrote this in a registered will. Also by a family agreement in Rs.10 stamp paper (duly witnessed but not registered), my wife's mother, my wife's brother and my wife (daughter) have stating that my wife (daughter) can build the ground floor and my wife's brother can build the second floor only. This is now contested by the deceased brother's wife and son claiming full rights for this property. Pls advise my wife can have rights to this proper