There seems to be a misunderstanding about feminine and masculine features for faces. I see people here saying that having big jaw, big chin is a masculine trait. There are plenty of low testosterone women with big square jaws: link
Girls do not look at a guy and think, "ohh he has more testosterone, he is manly ;) ". It is the features. For example, I love defined cheek bones, do not really care about if that is testosterone. It is just a trait that is considered attractive. I picture a cowboy when you said strong jaw, which is attractive/manly. Personally, I like a defined jawline, not neccesarily a big jaw.
That's something that I actually find really attractive in guys. But it's not because I think it's manly, it's just a focal feature. Something different. Often, you can see strength in a jaw like that, and that is certainly something found traditionally attractive. Often, the guys with bigger, more defined jaws are bigger anyway. Also, there are a lot of girls who have really defined jaws, but I have no idea why that's attractive. lol You'd have to ask other guys about that
Modern Manlyness isn't defined by just your testosterone. Its ruggedness. Big jawlines are a nordic trait, beckons images of big rapine vikings making their way, that's a manly image; of course, all shaved and trimmed for the modern ladies, haw-haw.
Because generally BIG is masculine, while small is feminine... I take it you have a triangular jaw line and are jealous for some reason. Stop hating... It's a preference thing. Guys like Johnny Depp have a triangular jaw line and get plenty of girls.