What were the changes that occurred in Chandni when she experienced the fascinating hilltops?

Abbu Khan was the guardian of Chandani. When Abbu Khan brought the young Chandni to stay with him she was happy. She heard the tales told by Abbu Khan. She used to listen to the stories with a lot of interest and affection. But when her fascination for hills grew, she lost the interest in Abbu Khan’s stories. Later she had no more interest. Chandni used to relish the juicy grass offered by Abbu Khan, but soon she lost her appetite and grew very thin. She did not take any interest now. She used to stare at the hilltops and imagined herself breathing in the free air of grassy slopes. Finally, she had no charm in Abbu Khan’s house.