Clearly we're all whirling about this. She only survived one round at the USO, and they did say that the bad test was at the USO. She would have played between 29-31 August, and it's hard to think that that's not the window when they would have tested her. Anything else doesn't make sense. As
@MargaretMcAleer says, she tweeted some pictures of herself having had some kind of surgery on her nose on 15 Sept., stating breathing problems at the USO. As Margaret also posted, just above, there is no reason for her to use this particular drug, other than performance-enhancing.
I saw no mention of how much of this drug was in her system. However, unless something else she was taking for her nasal surgery, etc. presented itself chemically as this drug, it would seem like she took it. And if she did, it's hard not to think she did it knowingly. It will be interesting to see how her doctors and lawyers mount their defense.