She was born in Australia, moved to the United States at age three and was raised in Cottage Grove and Eugene, Oregon.

[2] She performed the Hall & Oates track "Maneater" for the soundtrack of the film The Secret Life of Walter Mitty.

Her follow-up EP Raceday, produced by Mark Foster and Rich Costey, was released in November 2015.

[4] The song "Jitter", from Raceday, was singled out for "earning an avalanche of internet buzz," with prominent DJ and BBC Radio 1 host Zane Lowe saying it "might be the song of the year so far" while describing Mitchell as "absolutely a new contender in the pop world.

"[5] In 2017 she released a number of singles, including "Kids (Ain't All Right)", "Bae", "Now", "Cali God", "Come Back for You", "Capital Letters", and in September of that year, "French Becky", co-written by Nate Donmoyer and Kam Mohager, with Cara Salimando and Mitchell.