That would be a contributing factor. It is what put her in a vulnerable state, though it was not the direct cause of her death. She survived that injury, and would have continued to survive, if she hadn't been starved and dehydrated to death.
If you were beaten, and left to die, that beating would be the manner of death. But if you survived, and during your recovery someone came along and shot you dead, the shooting would be the manner of death.
Exactly. The M.E. stated that he had no idea why I was beaten or if I was. I just died. "Manner of Death: Unknown"