Well, honestly, the rate of weight loss depends on her diet and/or training as well. Is she training now? How about her diet? Is it in check too?
If she's going to use ephedrine, I would stack it with caffeine as well.
You can get some good herbal blends of that stack if she would rather go herbal. Does she have access to 8mg or 25mg ephedrine tabs?
A good stack is 25mg ephedrine, and 200mg caffeine. That is of course providing she has no health concerns.

Hi! She Isnt training right now but she has been for about 3-4 years now. and she is gonna pick it up again. Her diet is good, she is on a twinfast diet right now with 700 calories per day. Im not sure about her ephedrine tabs though. thnx!

700 calories a day seems too low. Her resting metabolic rate is probably around 1700 or so, so that's already a 1000 calorie a day deficit, which generally is the most people should push it if they're not obese. Add everything else in there, and she could be burning 2200-2900 calories a day, depending on how active she is. That can possibly be over a 2000 calorie a day deficit, which is way too low.

I have to agree with Frosty, those calories seem WAY too low. Please tell me that your sister isn't a woman who wants to lose weight by popping a pill!
She's going to have to base her weight loss program from the kitchen, not a bottle!

Noo, My sister has always been loosing weight on the basis of Training and dieting, she just wants to speed it up a bit.