Happy birthday, Shailene Woodley! The actress turns 23 today. Woodley first rose to fame with a starring role in ABC Family's The Secret Life of the American Teenager, following TV stints on The O.C. and CSI: NY. But it was a supporting role in the Oscar-winning movie The Descendants that sky-rocketed the California native's acting career. The George Clooney-fronted film led to major parts in the critically acclaimed Divergent series and The Fault in Our Stars---both YA novels-turned-films earned Woodley the coveted title of leading lady. In honor of her birthday, we're taking a look back at the star's transformation.