Forsberg was born on 2 May 1994 in Jakobstad, Finland to a Finnish mother and a Finnish-speaking Swedish father, while being raised to speak only Finnish. Her parents were Baptist missionaries and Forsberg grew up a missionary kid. Because of her parents' career, she moved frequently as a child, living in Texas for five years and the United Kingdom for a year, before returning permanently back to Finland at age six. Forsberg spent a few years in a music academy in Jakobstad and later studied to become a chef before embarking on a singing career.
Forsberg was interviewed on British BBC Radio, Finnish public radio Yle and Swedish TV in which she confirmed that she was contacted by a Producer from The Ellen DeGeneres Show. For approximately 180 seconds, she was a guest on the show on 7 April 2014 and she took home a tripod and a camera as a gift from DeGeneres. The trip was documented in a short series titled Sara Goes LA which was produced by Finnish broadcaster MTV and has also been published on YouTube since.
In December 2015, the news broke that Forsberg had spent the last 18 months working with Lucasfilm and was the creator of the alien language used in Star Wars: The Force Awakens. She co-wrote the song "My Heart Wants Me Dead" by Lisa Ajax for Melodifestivalen 2016, as well as the song "Drip Drop" by Taemin from his second solo album Press It.
In July 2016, it was revealed that Forsberg had created another alien language for a Hollywood film, this time for the film Star Trek Beyond, in which she has also a minor voice role as an alien named Kalara.
Also, in February 2017, Forsberg began hosting Remotely Funny, a British game show on CBBC.
