Is it bad for a 14 year old to use sensa weight loss system?

im really concered about one of my freinds.she says that she wants to loose a lot of weight. and shes been talking about things that are for grown ups. like sensa weight loss system. shes a vegetarian who doesnt eat that much. she hates dairy products for some weird reason. every time i eat ice cream or frozen yougurt around her she just says no thank you i dont want any. she doesnt eat any fat stuff at all. no cake or cup cakes ice cream. if any thing she eats a couple patoe chips here and there. she mostly eats veggies i think. but the other day we were at the mall and we passed by a GNC store out side they have a weight machine that tells you how much you weight and you body fat. so she is 5"3 and weights 142.2 pounds and she is 25 pounds over weight. so she at least wants to loose 25 pounds. but what i dont get is that shes 25 pounds over weight? of eating what? she hates a lot of candy and ice cream. its weird but i never saw her eat any thing fatty like that around me, but her sister is 5"9-5"10 really tall could this weight be just baby fat that she is gonna use to grow. she wants to use sensa. sensa is powder you sprinkle on you food for your brain to think that your body is full but she bearly eats! she eats veggies and thats it. she want to take this a long with vitamins and she still wants to go to the gym is this healthy for a 14 yr old? p.s shes turning 15 if it matters?