she will have trouble sleeping..get headaches and could become easily irritated.
if she's only 10-15 lbs. overweight, no doctor will condone a diet pill with a bunch of herbs and heavy caffeine...I think they allowed Ephedra back to US sales but may have taken it off again...is she looking for the energized effect or appetite supressant?
take her pulse for her resting HR...I'll bet it is pounding...it's not a good thing even if she is strong and in good physical shape.
if she is taking it because she is tired, there might be an underlying cause, she should go to a doctor and get a blood workup to determine if she has a deficiency or possible anemia....(that's what i would do for myself)
If she wants an effective "diet pill" let her use Alli...which is a liphase inhibitor...only works on the GI tract with blocking a portion of her fat intake...but has unattractive side effects when you eat too much fat in your diet...(oily anal leakage and poo).
..my daughter used the prescription form of Alli, Xenical...when it first came out..she lost 50lbs. by eating properly and exercising in about 6 months....and it kept her honest about her diet...from the fear of what she could expell.