Answer

Nandivardhan’s sister was Trishala according to some traditional accounts, but this depends on which Nandivardhan is being referred to.

If you mean Nandivardhan, the elder brother of Bhagwan Mahavir, then the commonly known family relation is:

• Father: King Siddhartha
• Mother: Queen Trishala
• Brother: Bhagwan Mahavir

Clarification

In Jain tradition, Nandivardhan is mainly remembered as the elder brother of Bhagwan Mahavir. The name of a sister is not as commonly emphasized in standard popular accounts.

Takeaway

Nandivardhan is best known as Bhagwan Mahavir’s elder brother.