Firstly, I would make her realize that she speaks loudly and this is not appropriate. She should speak softly in order to be graceful. Secondly, I would tell her that instead of giving all the answers in the class why don't she indulge in creative writing like writing poems etc.. By doing this she would utilise her energy in something productive, would build up good rapport in the classroom and slow learners will get a chance to speak up in the class.