My friend wants to get down to 110..help!!?

My friend is currently about 155 pounds and wants to weigh 110. She works out to insanity and billy blanks jr..she lost about 50 pounds but not from doing those workouts..from not eating previously...she has loose skin on her stomach and alittle on her thighs..how can she tighten the skin on her belly? Is there any creams that are proven to work? Also what exercises or workout programs do you guys recommend that will make her lose weight? She likes military workout programs..but cannot afford to go to a gym..Any help is greatly appreciated thanks. She's about 5'7 and wants to model..thats why she wants to get this thin by the way.