I know the only safe way to lose weight. The main thing here - not to be offended, but to understand that absolutely all the diets and patented weight loss techniques involve only slimming of your wallet. Yes. But if you completely throw this problem out of your head, the weight loss will happen by itself.
To lose weight you just need to burn more calories than you consume. Working out might help, but only if you're still able to control your diet. Just tell your sister to make sure she's a little hungry all the time - don't make her starve herself, but just not eat like a maniac.
the only way i have found for losing weight is to do skipping, rope skipping is a very good exercise to reduce weight.
You can go to Google and search for some online help or you can check this http://www.google.com/#hl=en&source...qi=g10&aql=f&oq=&gs_rfai=&fp=d1130564c93b4a66