I know the feeling when you're tired of looking in the mirror and knowing your body could look better if you just put the effort in. Whether you need to lose a few pounds/kgs or you could do with a bit of toning, these are some awesome pics I have collected which I placed around my room to help motivate me to exercise every day.
Please note it is important to remember not to over do it. You should be doing a minimum of 30 minutes of exercise every day, but no more than an hour and a half. Once you go over 90 minutes of exercise, you won't get any results - in fact you might cause yourself to move backwards. You may feel constantly fatigued, tired, and the chance of muscle injury is a lot greater.
At the end of the day, this isn't about changing yourself, but about improving yourself.
An appropriate work-out schedule for teenage girls will be posted soon.
Remember to stay healthy! Eat well and drink loads of water.