Hindu Muslim Marriage

Hi, I am a Muslim boy who wants to marry a Hindu girl, we plan to do so through special marriages after which, My parents want to perform the ritual of a nikah, I have convinced them not to get the nikah nama signed but my to-be wife is scared that she will become a Muslim after performing the rituals. I have the below questions : Major Question - Will she be considered a Muslim if she performs the ritual? 1) What are the points to prove that she will not become a Muslim just by performing the ritual? 2) How can i ensure her that legally she will be a Hindu regardless of the ritual? 3) What will be the religion of the children? 4) Can we keep the religion of the children black on official documents? 5)Can there be any legal action in case if the nikah is performed after the SMA registration? I really wish to marry her and do not want our life to get affected by this, no do i want my parents to lose their respect within the community. Please help !