Drain, your girl is normal. If she looks good now, what she's doing is fine.
She simply needs to stimulate the muscle, she doesnt need heavy weights for that.
Machines will work just as well as free weights for her goals. The reps should be between 8-15. Supersets are a great way to up the intensity. Train the whole body 3 x week, do some sort of difficult cardio, like sprints on the other day. This will give her the glutes every man and woman desire. Not on a treadmill.
She seems to understand nutrition, thats fantastic.
The only fat burners that work are illegal, ephedrine and clenbuterol, dont waste money on anything else.
Keep her exercising, because as you can tell, not all girls do. Dont give her a program she wont do. Add sprints into her training without adjusting anything else. Do it for a month, see how she looks then.
Keep telling her she looks great.