It's not my place to nitpick as I'm sure you probably are more seasoned in anatomy than me. Something's just not sitting right with the collarbone, it seems misaligned. Probably had something to do with your model. I serpose.
I know the shoulders/arms SEEM beefy. But they're not. Shading's playing a trick on you. The sketch wasn't like that at all, and I made no alterations to the lines, whatsoever.
Besides...
It makes sense actually, with who she is, the kinda life she leads. If I did less muscles, I could get away with it still, 'cause at the same time, this isn't real life =P
Thank you, though.