[3] Oviawe was born in Benin City and moved to Ireland at two where she grew up in the County Cork town of Mallow.
Oviawe's parents, Joy and Joe, named her after the actress Demi Moore.
She and her brothers were taken care of by their Irish stepmother Kim Carroll, with whom their father had two more sons, and their paternal uncle Courage.
[5][9] Oviawe attended Mallow No 1 National School and then Davis College, completing her Leaving Cert in 2019.
[11] At the latter, she played camogie and Gaelic Football, and starred in school productions of Beauty and the Beast, Grease and Sister Act.