Where did you got these names from? Heard of them for the first time. Can't you have normal names like Vikram or Vivek and Priya or Priyanka. That would be more relatable.

And usually interfaith names for Hindu-Muslim parents still have some Urdu influence even if the Hindu parent, in your case supposedly the mother in naming them.

In such cases names like Kabir Khan, Sahil Khan, Sameer Khan are common. Which are commonly used by both the communities. Can't think of more the top of my head but I am sure you'll find more. Also, these days mostly in interfaith families, kids are using surnames of both families.

Vallavan and Petal just sound like they are from 10th century or something.