25 mg is pretty high for women. generally speaking I've read between like 5 and 15mg is sufficient for women to dose. At 25mg she may start to see virilization start taking effect. She may need some liver support because even though she is injecting, Winstrol is still methylated. I would also suggest some form of cholesterol support as Winstrol can play with lipid profiles.
In my honest opinion she would be better off pushing anavar. From what i've gathered its much more mild and less andrgenic then winstrol, and she wouldn't have to bother with the injections.