R-Patz makes her feel like a natural woman.

Kristen Stewart's sexy-glam transformation is just about complete -- with the evidence on the November cover of British GQ.

The Twilight Saga: Breaking Dawn Part 1 actress, 21, wears a retro-sexy bikini, sporting bright-red lipstick and with her brunette locks in screen-siren waves.

What does Stewart think of her evolution? "I looked like a boy for a long time," she told GQ. "Now I feel like a woman."

It's not the first time fans have seen the superstar stripped down, of course: in sexy honeymoon scenes in Breaking Dawn (out next month), she and real-life love Robert Pattinson, 25, frolicked in the swimsuits at the beach in St. Thomas.

Tell Us: What do you think of her bikini bod?