I watched The Edge of Tomorrow yesterday and I think I heard the background news report mention the Angel of Verdun had 100 kills in Verdun, and not long after it was said she had 300 kills. Did anyone else notice that? If so, how is that possible? That battle already occurred in the past, before Cage got the ability.
As the movie is not on DVD or anything similar yet, I cannot link to proof of this answer. I saw the movie twice and they never said she killed a hundred. They always said hundreds of kills. You may have not heard the plural "s" in the theater, but I assure you, it's there. From the beginning she is credited with "hundreds" of kills.
Sorry it's not possible to back up my statement, but lack of proof does not mean I'm wrong. Time will get my back on this one.
She died 300 times - after seeing her friend die 300 times. But during that time she became more skilful, and more importantly, like Cage after her, she learned where the mimics were, and what they were doing. Each time she was able to kill more. By the time she was wounded and lost the ability to reset time, she was able to kill hundreds and win the battle on her own. After that she was just like any other soldier, only more experienced at killing mimics.
What is not explained is why France was overrun if humans won at Verdun.