Her and her friend Natasha Oakley founded a bikini company and subsequently gained thousands of followers on social media (mainly Instagram) due to their frequent bikini pictures.
For the lazy: https://www.instagram.com/devinbrugman/
and her friend: https://www.instagram.com/tashoakley/
It is a wig made from her own hair.
edit: that is what I read here, but then on Kimmel last month she said it is a wig from Russia, so I'm not sure which is true.
This picture was up in my room for a long time, but this next link is what you're after...
This is from the 'Silver Linings Playbook' photocall at the Toronto International Film Festival - September 7, 2012. One of my favorite pictures of her, here are the rest from that event - http://imgbox.com/g/OVzvyIgV0S
/r/JenniferLawrence
A Very Long Engagement, directed by the same guy as Amélie is good too, although I still much prefer the latter.
Have you seen her ad for Chanel? It's the definition of classy ;) How I fucking envy the guy.
No, you're getting downvotes because she's actually from the UK.
https://www.instagram.com/rachelwilliams_uk/
Edit: In case anyone was wondering, the comment said, "Ah yes, Americans and their obsession with basketball-sized breasts..." and had an edit complaining about the "butt-hurt Americans" that were downvoting him.
She wrote a book recently apparently she is really big on atheism and the harm of evangelical christianity lately.