The age of the woman doesn't really matter so much. What is really more important is what she is trying to accomplish by taking it. Trying to "lose weight & tone up"?
Before giving any advice on use of any AAS, esp for a woman, my first question is what is the reason for it? Then what is her current diet, training and purpose for doing it? If the diet & training aren't well-established & consistent already, I don't recommend throwing in any AAS. All of that stuff is on a SUPPLEMENT to an already existing, well-established diet & training program (and more than like "I just started training a month ago & not seeing any results, my boyfriend suggested winstrol to lean me out").