Weight gainers?!

Weight gainers?

hi i recently went to GNC and purchased a weight gainer called Pro Performance Weight Gainer 1850. See i really underweight and want to gain between 10-17 lbs. I've been reading and it said that the weight gainers make you fat, is it true. I do want to gain weight but not fat. So how long do you think it will take me to gain the weight and how much fat will be added on? Should i take this everyday with regular meals? What exercises should i preform? do you think its a bad idea my parents are making me. i lift 5lb weights everyday for20-40 minutes.
im 13 year old female, 5ft 5 in and weigh 102lbs.

At thirteen, you don't need to be worried about gaining weight. Many thirteen year olds are naturally underweight and its perfectly healthy and normal. And yes, weights gainers will cause you do gain fat instead of muscle if you choose not to work out with it. If you did vigorous strength training exercises you'd probably gain more muscle. I don't think 5 pounds weights are going to cut it though. I would stick to a healthy diet and not worry about my weight. You'll fill out naturally as you get older.