All her pokemon have perfect IV's (31 in every stat), most of them have 252 EV speed and 252 in att/sp att. You may think its hard when you look at that... but you are a human who is able to think, use other pokemon, use items (more than she can), change your strategy... There is no reason to not be able to beat her. Get this 3 things and you cant even lose, trick room (hint: bronzong), rain dance and flash fire.