Basically, there's this girl whose name starts with an O or possibly an A or possibly I'm wrong altogether, and the title of the book is her name (again, I could be mistaken...). The story takes place in some...I would say more fantasy world, though think more realistic fantasy like Neil Gaiman type worlds than Lord of the Rings Middle Earth type settings. So it's not futuristic since there's no technology or anything. This girl belongs part of a tribe and I keep thinking "savage" only because it's more...barbaric? It has nothing to do with Native American tribes or any of that sort since it's a completely fictitious other world setting.
So in this tribe, a virgin girl is sacrificed every so often...and she's to be sacrificed. I could be mixing wtih something else because this sounds a bit too graphic for YA but I believe she's meant to be raped by several men before she's set on fire in this tent. Anyway, basically she hides a knife in the ceremonial outfit and manages to kill them and run away. She then somehow ends up in a more "civilised" community. Again, not futuristic, nothing complex, just like your typical village or something of that sort. She ends up being a serving girl to this young woman who is very naive and sweet. The only other thing I can remember about this novel is a bunch of pickpockets or bandits or something trying to attack the "mistress" on the street late at night and the main character attacks them and manages to get her mistress to safety.
Random other details include...the main character has this...yell? Like a tribal scream a la Tarzan that's meant to be a war cry of sorts. She also comments that she's grown fat and soft as a servant, and the whole story is told in first person.
Anyway, any help would be appreciated since this is driving me mad!