Nicky was sent off to study in USA when she was seventeen, she did not returned to India ever, she found herself a job and husband there and settled down.
Her door was not open for Singh family, Mona never went there but her parents did, regularly and returned with their sob story to tell everyone, how Nicky is too busy to meet her parents.
Mona used to feel absolutely awestruck by perfect performance of her parents, a trait she picked up in later years, to dupe people and play victim. It took her years of practice though, first she had to build a perfect public image, image of fool and then utilize it.
She had brilliant role models, role models she could study all the time, that is, almost all the time, she did not had access to every part of their lives, only some.