If you're fat your boobs grow. If you get lean - as in REAL lean - they shrink. Now if you add test and you're lean then there's a possibility of gyno. But that doesn't seem like it'd be an issue with most women - unless you hate your boobs and or like being crazy lean. It also, test wise, comes down to just how much you use. Same as for guys only it takes a LOT less to have problems with it in women.
Mostly common sense really.