I also recommend that book.
However, here's the problem with any workout schedule: it's never going to work unless you change your diet. Your sister could be running 10 miles, but if her diet sucks, she's going to remain at the same weight or possibly lose some weight, but regain it right after the exercise stops.
Here's what I suggest you to do, buy the book that is suggested. It has an excellent section on nutrition that I found helpful.
At the end of the day, it's calories in versus calories out. If your sister is burning more calories required, she's going to lose weight, and the vice versa.
What needs to be done:
1) Find her BMR. Subtract roughly 500 from it. Consume the calories up to that number, and she will lose roughly 1 pound per week (maybe more initially). Eat good nutritional food. Stay away from fast food, and food on the go. Eat natural, good food such as chicken, salmon, tuna, etc. Eat 5-6 meals a day, each at about (YOUR BMR - 500) / 5-6 (meals) calories. Eat plenty of fruits and veggies with each meal. Be sure to drink plenty of water. Stay away from coke or other products.
2) Exercise is secondary. Exercise will help maintain any lost weight and with proper weight lifting and cardio, muscles can be kept and fat can be lost. Basically, any good program will have the following: 3 days of lifting weights (full body, no machines) at about 30-45 minutes per day. 3 days of cardio (running, cycle, elliptical, rowing, swimming, etc) at about 20 minutes with hitting your training heart rate. To find training heart rate, take 220 - YOUR AGE, then multiply it by .60 (or 60%, or multiply by .50 or 50% for beginner), this will be your training hear rate.
Good luck.
