Registered will deed

Dear I want your valuable suggestions in my case. My grandfather were 2 brothers and 4 sisters >Now only my grandfather(A) is married his brother(B) is unmarried >Out of 4 sisters only 1 is married who settled back to her brothers home after husband death >my grandfather had 2 sons X &Y >I am X's Son Now my grandfather brother(B) registered a will deed in favor of his 4 sisters Which was executed in tehsil court and all 4 sister got their share(even after death of 1 sister 4 sister got their name in records) Now the share they got in 4 khaata they made that merge in their account as 1 died Now three khaata for these 3 sisters One sister made a registered will to his brother( A) Grandchild(i.e Y's son) and left nothing to other i.e X child My questions are÷ Can she make will deed to his family member who is minor without giving nothing to others? Can she make will of ancestral property as she got through his brother which is ancestral? A will with not properly property mention that is no gaata, khasra etc is mentioned only village name is mentioned Can help me in challenging it? Please answer keeping Uttar Pradesh laws