She has written pop songs such as "FourFiveSeconds" performed by Rihanna, Kanye West, and Paul McCartney.

[5][7] She began a YouTube challenge where she posted videos of herself singing a new original song for 275 days.

[6] She was contacted by Joy Brown of Roc Nation on day 302 of the challenge and signed to the label.

[3] She also wrote the song "Die with You" performed by Beyoncé and "Break Your Heart Right Back" by Ariana Grande.

[8] In June 2020, Kirby posted a viral TikTok video about the racist origins of the pancake brand Aunt Jemima, and amid other online critiques taking place, the brand announced that they would retire the racist imagery.