Steriods are not the best option for females just looking to lose BF. The possible side effects can outweigh the possible benefits. No AS will help her lose BF without a good diet and training schedule.
Also, remember that almost ALL steroids affect women differently than men. For exmple, Winny is often used as a cutting drug for men. But Winny tends to majorly bloat most women. So please don't go off half-cocked and make up a stack for her without REALLY researching the pros and cons.
Losing 10-15 lbs of fat can easily be done with a C L E A N diet and a S M A R T workout program. What is her diet and workout schedule now? Chances are she is over-working out and under-eating (like the vast majority of females at the gym). Is she a cardio bunny? Does she lift at ALL? How long has she been working out? How old is she?
Have her post on the women's board. List her stats, her workout history, her current workout, and a sample day of eating - she'll get a lot of help there. But need DETAILS!
As a fat-burner, T-Rex is really great. I would get some of that for her. Either that or make your own E/C stack.