General:
I found your writing very confronting, I myself felt abused and I guess that was the idea. Your graphic descriptions place the reader in the characters position which with the given subject matter may be something some will not enjoy.

Plot:
Unfortunately I can't tell where this is going but thus far the use of the prologue is effective.

Character Development:
I don't know what the major character looks like really, I know she is strongly loyal and viciously determined but not a lot else, perhaps we could Know some more.

Structure:
As I said previously the prologue use is effective, thus far the structure is fine.

Tone/Voice:
wow! It is really graphic and centered on the violence involved. This is a tool that you use well, I felt raped...and I'm a 50 year old man. I wonder though if it may not be a little to confronting for some, do you care about that? Maybe you shouldn't.