While she was homeschooled, her mother taught her and Finneas the basics of songwriting. O'Connell and her brother had worked together on some music, while he had been writing and producing his own songs and performing with his band. O'Connell said her brother and her mother inspired her to get into music. Their parents encouraged the siblings to express themselves and explore whatever they wanted, including art, dancing and acting. O'Connell wrote her first "real" song at age 11 for her mother's songwriting class. The song is about the zombie apocalypse, inspired by the television series The Walking Dead from which she took script lines and episode titles that she added to the song as part of the assignment. O'Connell had gone on some acting auditions, which she disliked; however, she enjoyed recording background dialogue for crowd scenes and worked on the films Diary of a Wimpy Kid, Ramona and Beezus, and the X-Men series. She performed at talent shows and joined the Los Angeles Children's Chorus at age eight.