I dunno man.
I've played as mafia and did not put a vote on somebody for the first half of the game. It is an easy strategy to look good for the mafia. It is hard to be a suspect when you don't have suspects yourself.
I am not saying for certain she is mafia because nobody knows besides her, JB, and possible team mates, but I do disagree with your hypothesis that an absent vote makes her look better.
Deadshit and Facekicker are suspects to me because they think I am lying. They can always hide behind the facade that it is because it is mafia and that it is their job to find suspects, but really how much of a threat am I really? I will probably be dead by tomorrow anyway, so the smart mafia would ignore me, keep me alive and deflect suspicion on me to discredit me.
This is the reason why my vote remains on Deadshit. Deadshit is playing so awful that, if town, she is a great mafia asset regardless. I would like to give her the benefit of the doubt of being mafia rather than dumb and town.