Claim is irrelevant. Specific to Maryland Law, Assault occurs when one makes or attempts to make physical contact with another OR intentionally frightens another. Alice saying she helped to steal the car and your definition of the theft as "accosted Carol" implies one of the three forms of Assault took place. Alice just admitted to commiting the crime she thought was wrongly charged to her.
The crime she was trying to get out of is called "Assault and Battery" which is where Assault leads to actual injury or physical harm to the victim OR attempts to actually injure or harm another OR puts them in fear of such action.
In Maryland Law, the Battery portion almost always is paired with assault while in other states, it might be possible to commit Battery without Assault (though in these states, normally a separate assault charge to Battery is usually added.).
As a helpful tip, the two words general break down as follows:
Assault: The act of threatening harm or making unwanted non-injurious contact with another person.
Battery: Causing Injurious Harm to another person.
In Maryland, Alice was rightly charged with assault. Upon capture, Bob will recieve an "Assault and Battery" charge for hitting Carol with the stolen card and may get an addition simple Assault charge for the threats before he drove away.