It depends how lean she wants to get. With gals, less is more. As I'm sure you know, steroids can cause some serious irreversible side effects in females. Even the "safer" gear can cause issues, such as increased body hair and facial hair, upset stomach, acne, and other sides. If she wants to run steroids, be sure that she does some more reading on the gear she is going to use.
Backtracking, the first thing I would use for a female looking to lose fat, is clen. I would start at 20mcg and add 20mcg E2W, until she reaching 80 mcg and stay there. At some point, I would add yohimbine HCL, as it is good for dealing with estrogen related fat. around 2.5mg 1 to 2x day. If she wanted to take it further, I would later add nolvadex 10mg for several wks, then 20mg for several more wks. This will help to dry her out and harden her up more. All of this will work very well for her, and we haven't even had to resort to using AAS. In a lot of cases, steroids can complicate a fat loss plan for females. Even REAL anavar or winstrol can cause bloating in girls. I know, this doesn't make sense based off of what we know about men and AAS use, but I have seen it a number of times. If she does want to use gear, I would stick with anavar for the time being. I would start at 5mg and see how this low dose effects her. Some girls will see sides on 5 mg. Some will see sides at 20mg. You're best starting as low as possible and then as long as she is seeing results, stay at that dose. If, down the road, after a number of anavar cycles, she wanted to try something else, primo would be my next suggestion. It has a higher potential for sides, but still on the safer side. 50 to 100mg EW. Stay away from the winny, if possible. I've seen winny deepen many a womans voice. When it happens, it happens fast and once you realize what is going on, it's too late.
So lets assume she is dieting for 16 wks. Here is how I would outline it
anavar (if she desides to go that route) starting at 5mg, going no higher than 20mg, 10mg should be plenty, split into 2 daily doses
Please make sure she reads my reponse for herself.