what to do

There is a student in the class that I work in who seems to always shout out and has been told numerous times to stop as it is disrespectful. I have tried to keep her behind in break times to reinforce that this is unacceptable behaviour in the class. In addition to this, she always seems to ignore adults and has to get the last sentence out of the conversation. The parents also know this is going on. Any advice or tips, as I'm an NQT?