Write a note on the grandmother’s side of the family. What was the reason for the breaking up of the family?

I'm not sure about the family breal up part. Tha'mma is the young boy's, the narrator's, grandmother. Tha'mma was the headmistress of an all-girls school in the city where the young boy grew up, Calcutta (Kolkata) in India. Tha'mma is a strict person. She is highly respected, and very patient. Tha'mma is not very fond of Tridib and unlike the narrator, she doesn't really give much preference to Tridib or his ways of thinking.