Fat loss supplements aren't the answer to her losing fat right now. If she is having such a difficult time losing fat without a fat loss supp, something that she is doing needs to change.
Be sure that she is eating enough lean protein, healthy fats and carbs (mostly veggies, and lots of them!). She should be eating 200-500 calories under maintenance level. If she is eating too much obviously she will not lose fat, and if she is eating too little her metabolism will slow down and prevent her from dropping the fat.
Once her diet is on track, her routine should be looked at. I would suggest that she weight lift 3-4 days a week, doing full body routines each time. Incorporate movements like: deadlifts, squats, clean and press, pull ups, dips, chin ups, push ups, bench, lunges, step ups, rows etc. These are compound movements that will definitely be difficult. She needs to push herself hard every time she lifts or it is really near to being pointless. She shouldn't be afraid of lifting HEAVY- lifting hard and heavy is what will kill that fat!
Adding some HIIT on her off days of lifting will speed up the fat loss progress.
Now, as for supplements: Right now the only supplements she needs are BCAAs, which will help with maintaining and gaining muscle (making it easier for her to drop fat) and possibly protein powder to help her with getting in enough protein every day.
Along the line, as she is seeing fat loss progress, adding a fat loss supplement may help her out some. But everything above needs to be addressed first, and progress ALREADY needs to be occuring.