non-Muslim family members

Calling a Muslim by their non-Muslim name

Q: I am a converted Muslim after marriage and I really feel good that I have become a Muslim. I have also changed my name after marriage. My previous name was Nancy Nicholas and my Muslim name is Aaliyah Ali but my parents and sisters are still Christian, and they call me Nancy only. My husband doesn't like it and I cannot tell them not to call me Nancy because they will feel bad as I married so early when I was 18 and they wanted me study and do something for them. So I want to ask you:

1. My husband says, if they will call you by your previous name, you will be in gunah or crime and Allah doesn't like it.

2. Also I want to ask whether it is really important to change the name after marriage if you have a non Muslim name?

3. I heard that on the day of Qayamat everyone will be called by there names so which name I be called Nancy or Aaliyah?

Making dua for the Hidaayat of non-Muslim children

Q: I have adopted Islam and married a Muslim man. I have two daughters from my earlier marriage who was a Hindu man. My daughters have not adopted islam yet. We keep on trying to make them understand and adopt Islam. My elder daughter is fifteen years old and younger one is 13 years old. Elder daughter gets angry whenever we talk about changing religion and wants that we should not talk to her regarding religion in future. Younger one says she will very soon adopt Islam. I want to know how should my husband interact with my elder daughter after knowing that she will never convert to Islam? I also want to know can my husband make dua for them as they are non-muslims but they are his daughters?