She was convicted. In the U.S., I believe a person who was convicted, but the case overturned can be tried again. Look at that Marine.
No, she was first acquitted. She was convicted in the second trial. Under U.S. law, she never would have stood trial a second time because that would constitute double jeopardy.
This is the same justice system that convicted and jailed a world renowned scientist for manslaughter, for his failure to predict an earthquake.