Arni's first book, The Mahabharata: A Child's View, was published in 1996, when she was 11 years old.. It was translated into several European languages, and won the Elsa Morante Literary Award from the Department of Culture of Campania, Italy, among other accoladates.
As an adult, she has written two books based on the Ramayana. The first, Sita's Ramayana, is a graphic novel developed in collaboration with Patua artist Moyna Chitrakar. It was published in 2011, and spent two weeks on the New York Times bestseller list for graphic novels.
Her second Ramayana adaptation is The Missing Queen, a speculative-fiction mythological thriller. It was published by Penguin/Zubaan in 2013.
Arni is an alumnus of the United World College in Italy. She has lived in Indonesia, Pakistan, India, Thailand, Italy and the USA.
- "An Unusual Epic". Retrieved 28 August 2018.
- "In Search of Sita". Retrieved 28 August 2018.