People Magazine: Game of Thrones Star Keisha Castle-Hughes: Childhood Fame Was Bizarre

Keisha Castle-Hughes is a natural at playing a young warrior on HBO's Game of Thrones.

But then, she's had a lot of experience with fighting for her survival since bursting onto the Hollywood scene when she was only 13. In case you've forgotten, Castle-Hughes was the 'tween from New Zealand who, at 13, became the youngest person ever to receive a Best Actress Oscar nomination for her starring role in Whale Rider. The milestone had a profound effect on Castle-Hughes, who had never acted before she was plucked from obscurity. "I was so young," she recalled to PEOPLE. "Of course, as a child I'd had grandiose dreams of growing up and moving to Hollywood. But I think every little girl has those dreams, you know? There was a huge amount of pressure to continue on with it while various people were telling me this is the beginning of the end of my life if I didn't utilize the opportunity to work. I was like, 'But I'm 13 years old!' "

By the time she turned 14, Castle-Hughes was diagnosed with depression. "It wasn't crazy surprising because of the experiences I had. There was, like, these massive highs at the Oscars hanging out with Julia Roberts and then lows like going back to school in a low socioeconomic area in Auckland," explains Castle-Hughes. "[It was] very bizarre."

Meanwhile, Castle-Hughes was dogged by the worldwide press, especially when she became a teen mom, delivering now 8-year-old daughter Felicity-Amore in 2007. Reporters in New Zealand, in particular, were laser-focused on chronicling her every move.

"For a long time, I was maybe the biggest celebrity in New Zealand because a lot of other celebrities had left," Castle-Hughes recalls. "It would be like every week [someone would write], 'Oh my God, Keisha went to the supermarket this week.' I have a big family" – the actress is one of five siblings – "and we go once a month, so it could be, 'Why does she have two carts at the supermarket and why are they full of food? Does she have an eating disorder?' " Now 25, Castle-Hughes recently celebrated two years of marriage to deejay Jonathan Morrison and is adjusting to being back in the spotlight. "It took a lot of hard work to get back here," she tells PEOPLE. "I've finally come to a point in my life where I'm not looking for any validation from anyone, which is nice."