If the indictment says is a defendant instead of is the sole defendant, does that mean that there are more defendants involved?

A friend of mine was an office manager for a physician. She was questioned by the FBI and the US Attorney. The physician was indicted last week. It says on his indictment, that he is a defendant. She is convinced that she will be indicted too, even though she was just taking dictation from the doctor. The indictment was unsealed last week. If she were in trouble, wouldn't she have been named?