She won the young adult fiction prize at the 2014 Prime Minister's Literary Awards for her book, The Incredible Here and Now and the 2022 Writing for Young Adults Victorian Premier's Literary Awards for her book, Girls in Boys' Cars.
Castagna was born in Australia, but travelled with her family and lived in North America and Asia.
[2] In 2015 she graduated from Western Sydney University with a PhD for her thesis "Space, anxiety and the politics of belonging in suburban Australia".
[1] Her first novel, The Incredible Here and Now, won the Young Adult Fiction Prize at the 2014 Prime Minister's Literary Awards.
It was also shortlisted for the 2016 Adelaide Festival Awards for Literature Young Adult Fiction prize.