Does a Daughter of my brother have any right over the property ?

my father passed away in 2010. we are 2 brothers. my elder brother has a daughter. my mother has 100 % shares in the property my father had. after his death my mother is the owner of the property. my brothers wants her to give 33 % of rights to his daughter. Does the Daughter of my brother have any right on the property? and my mother has made a will of her share as well. in such a case what can be done?