What is the best workout and diet plan for a 13 year-old girl who is 4'8 and weighs 87 lbs with big thighs and a fat stomach that is a cheerleader so needs to be flexible and wants great abs?

For a 13 year old girl, I'd suggest doing push ups, sit ups, and try not to eat so much. Limit unhealthy snacks and eat plenty of fresh fruits and vegetables. Instead of drinking soda, try milk and water (because those are the healthiest drinks). Limit going to restaurants, and when you do, order fruits or vegetables instead of fries with your entree. And, if you need to be flexible, then stretch often. Also, ride your bike and exercise often. If you are still experiencing weight issues, try going to a doctor or check your weight online on the BMI for children website. And for a 13 year old girl, 87 pounds sounds under weight, and it seems weird to have a big stomach considering how much you weigh, so try going to a doctor, there could be something wrong with your body. Once you loose the weight, try to keep it off, even though unhealthy snacks taste so good, they aren't good for you, so try to not eat them as much.