Answer

In Jain tradition, Sunandā is known as the mother of Bhagwan Rishabhdev, the 1st Tirthankar.

Her brother was Nābhi Raja.

Explanation

According to Jain tradition:

• Nābhi Raja married Marudevī Mata.
• Their son was Bhagwan Rishabhdev.
• Sunandā is also connected with the royal family in the life story of Bhagwan Rishabhdev.

Takeaway

The brother of Sunandā is traditionally understood as Nābhi Raja.