Rose Arianna McGowan, the second eldest of six children (plus two half-siblings), was born 5th September 1973 in Florence, Italy to Daniel and Terri McGowan. Daniel is an American artist and Terri a French-American writer, and today a worker for Microsoft. Rose was born in a barn with the assistance of a 89-year old midwife and was raised in communes of the Children of God/The Family cult while her father was the leader of the Italian chapter. "From the outside it would be considered strange, but if you grow up in it, it's normal. I suppose all children are at the mercy of their parents, and whatever trip they happen to be on, and my parents were tripping pretty hard." Overall, Rose regards this period of her life quite positively and mentions often playing outdoors with her siblings and pet lamb. She does not remember so much of the Child of God ideology or being imposed to the scandals – except hairy legs. "It didn’t really mess me up being raised in a commune. It was a really idyllic part of my life. I mean, I grew up surrounded by rolling fields and playing in castles that had been cannonballed in the 14th century. What messed me up was moving to the States,” she said.

Through her father’s contacts in the art industry, Rose became a child model at the age of three and appeared in Vogue Bambini and various other Italian magazines. She showed exceptional intelligence from an early age. McGowan learned to read at three and by the time she was six, she was already reading "The Raven" and "The Tell-Tale Heart”. She was also a very stressed out child who possessed an eye for injustice. “Apparently, I'd get very angry if my dad wasn't treating my mom right, or if I saw any injustice.” The legend tells that McGowan’s father left her mother for the nanny when Rose was nine years old and they divorced shortly after.