She was inspired by the example of her mother , Dr Josiane Serre , a chemist and president of the Ecole Normale SupÃ rieure de Jeunes Filles ( ex-S Ã vres ) , the equivalent of one of the Seven Sisters . Her mother , Dr Josiane Serre , was a chemist who became the director of the Ecole Normale Superieure de Jeunes Filles .