How is Edmonds able to escape from the Confederate Army and rejoin her superiors on the Union side?

She rides off as soon as she is given her horse, crossing enemy lines into Union

territory

In the heat of battle, she manages to cross over to the Union side, where an

officer recognizes her

While Captain Logan is celebrating his recent wedding, she steals a horse and

rides off during the night

She reveals her true identity and convinces Captain Logan that she cannot in

good conscience fight as a rebel,