Married Daughter's right in ancestors property

My father had sold an ancestral land in the month of June and all formalities were completed subsequently. During past one year our relations with my Brother in law soured as he was not returning the borrowed money. As my brother in-law came to know about land being sold he had convinced my sister and she has sent a notice in December via SDM claiming land was sold without her knowledge and consent and she wants her share. As per my understanding married Daughter's too have right in ancestral property but not sure about once it's sold and claim coming after few months later. My father is not willing to give anything and is thinking of disowning my sister but I feel it won't help as it's ancestral property. Q1. Wanted to know what legal option do we have. Q2.Around 25% land was purchased by my Grandfather and as per my knowledge that is not considered as Ancestors property but we don't have any documents as it was bought 50 years back. is there any possibility for this purchased land to get exemption. Q3. Is there any share of mother too in case we have to get money divided or only I, my father and sister will have share. Many thanks for your help and advice. Note: currently I am working in Kolkata but land was in UP and my family also stays there only.