The 33-year-old, who has appeared in movies including 127 Hours, The Ring and The Sisterhood of the Travelling Pants, broke the happy news in an article for Glamour magazine, and used her pregnancy announcement to make a strong political statement about the upcoming US election.
She opens her piece by recalling a recent phone call she had to make to her mother after a story about an ex-boyfriend assaulting her went viral. To her surprise, her mother had her own story to share - and her grandmother's response had been less than sympathetic, telling Amber's mother: 'Boys will be boys. You just have to be really careful around them.'
'Boys will be boys and girls will be, what?' Amber wonders. 'Quiet. Hungry. Subservient. Game.'
'I've been thinking about motherhood a lot lately,' she writes. 'What it means to be one, what it means to have one, what it means to know one, what it means to make decisions as one and have conversations as one.'
'I am very lucky to be surrounded by strong mothers, from my own mom to some of my best friends—those who are raising young women to accept themselves and those who are raising young men to accept women.'
'Motherhood has been heavily on my mind because I am going to be a mother soon. I'm pregnant, with a daughter on the way.'
She adds that she hopes that her daughter doesn't have to inherit the language that's currently used to discuss women, and believes that Hilary Clinton is the right candidate to address the conversation.
'After I'm done writing this, I'll go back to my desk and fill out my absentee ballot. I'll be voting for more than just a woman; I'll be voting for a revolutionary idea,' she concludes. 'I'll be voting for a future for my daughter where conversations about our bodies and our lives are broader than what value they have for men.'
'A future where being a mother is less about warning our daughters about our sons and is instead lifting them up to their greatest potential. A future where my girl will someday say, "Donald who?" and think nothing is revolutionary about a woman becoming President. A future where she can't even believe that was ever even a thing.'