Why was Phatik's mother relieved when he was taken away to his uncle's place?

Bishamber kindly offered to take Phatik off his sister’s hands, and educate him with his own children in Calcutta. The widowed mother readily agreed. When his uncle asked Phatik If he would like to go to Calcutta with him, his joy knew no bounds.It was an immense relief to the mother to get rid of Phatik. She was merely driven by a prejudice against the boy. She was in daily fear that he would either drown Makhan some day in the river, or break his head in a fight, or run him into some danger or other. At the same time she was somewhat distressed to see Phatik’s extreme eagerness to get away. Phatik, as soon as all was settled, kept asking his uncle every minute when they were to start. He gave away to Makhan his fishing-rod, his big kite and his marbles. Indeed, at this time of departure his generosity towards Makhan was without measure.