Although it proved a harrowing experience – she fled with her family, she says, once the cult began advocating child-adult sexual relations – as the setting at first "was really idyllic," remembers the actress, 38, who rose to fame on TV's Charmed and now stars in Conan the Barbarian 3D.
"I grew up in pastoral settings" – specifically, the Italian countryside, where her parents were members of the local branch of the Children of God. But McGowan, who was born in Florence, knew instinctively that she didn't belong in such a place.
"I've always been who I am," she says, explaining that while she did believe in God, she wasn't in accord with the hippie lifestyle, and certainly not with their aesthetic or the subservient role of females in the sect.
Even at her tender age, McGowan rebelled. "I did not want to be like those women. There were basically there to serve the men sexually," she says.
When her father began to fear that Rose might be molested, she says, "My dad was strong enough to realize that this hippie love had gone south."
She fled the Children of God with her father and siblings and moved to the U.S. McGowan recalls that "it was not an easy assimilation" into the mainstream way of life. "My brothers and sisters, we thought everyone was boring."
Courtesy Rose McGowan
Looking back at her early experiences, McGowan deflects with humor some of the dangers and difficulties she faced. In contrast to the dressed-down hippie look of the cult, she says, "I came out of the womb waving red lipstick."
Still, the remembrances left quite an impression. While expressing gratitude to her father, who died in 2008, McGowan tears up. Mostly, though, she realizes the experience is all she ever knew and made her who she is.
"There are people who will read this story and think I had a strange existence," she says. "I think they've had a strange existence!"
For more on McGowan's time in the cult and photos of her childhood, pick up the new issue of PEOPLE, on newsstands Friday