Yes she probably used it, that's when she can be ticketed, she shouldn't be fined on a presumption.
Edit: Reading the note the charge is using phone while driving, not carrying the phone in unsafe manner.
Also I despise people using their phone while driving, the point here is that they must charge people for a valid reason and with proof of the infraction.
To preserve our privacy? (insert Padmé and Anakin stare meme)