Under the 'stand your ground' provisions of the Texas law she was under no obligation to try and flee. It was her car, she believed he was trying to unlawfully enter it, she had the right to protect herself with whatever means she felt was necessary.
Zimmerman appears to have been within the law, and this woman appears not to have been, on the basis of what is known and the law.
Wrong. Read the Texas law. It clearly states that the use of deadly force "...is presumed to be reasonable if the actor knew or had reason to believe that the person against whom the deadly force was used: (1) unlawfully entered, or was attempting to enter unlawfully, the actor's habitation, vehicle, or place of business or employment..." If he walked up to her car and tried to open the door without her consent, as she claims, then she was justified to use whatever means she thought necessary to stop him. Like it, don't like it, it doesn't matter. The law is the law, and the law appears to be in her favor in this case.
By the way, it seems to have been confirmed that the dead man had two bullets in his chest. That does not appear to be very supportive of the woman’s claim.
In what way? She said she shot him.
Was he still attempting to enter the vehicle after the first shot when she subsequently exited the vehicle, went after him, and then shot him twice in the chest???