Here's a Q'orianka Kilcher photo album:
Q'orianka Kilcher: Arrested at the White House
including this shot:
I'm guessing Kilcher's Quechua people don't wear headdresses like this. If they do, I'm guessing young Quechua women don't wear them.
Perhaps Kilcher is wearing it to "honor" the Amazon Indians she's fighting for. They may wear headdresses like this.
But they probably don't wear the headdresses with slinky black dresses. In other words, this looks about as culturally inappropriate as James Cameron in a headdress.
That Kilcher is part Quechua doesn't give her license to wear somebody else's headdress. I'd say this is another example of the hipster headdress phenomenon we've seen recently.
For more on hipster headdresses, see Indian Headdresses at Sasquatch! and Yale Grads Wear "Silly" Headdresses. For more on Kilcher, see Kilcher Arrested at White House and Kilcher Is Passionate About Activism.