I'm not sure how she gained access to this account. I personally logged into the ex's cell phone providers account page online (I paid the bills and this was right after she dropped the bomb) and erased that account from the payment options.
The ticketmaster thing was an account that I forgot had my mom's cc on file for quick purchases.
She knew better. Let's assume that she thought she was using her checking account to pay the bill...she makes $400 a month. This was done a month and a half ago, I'm sure she would've realized something was amiss by now. How could you pay two months salary and not realize that the payment didn't go through? She uses people and no one has ever done anything about it.