Here is a woman in a dress, something she might wear to convention about programming if she wanted to wear a dress: http://dressforweb.com/wp-content/uploads/2014/05/Korean-ver...
It's fairly modest and not loudly styled. This is not the same style of dress as a man wearing a suit. The equivalent for a woman would be this:
http://www.acrdepos.com/wordpress/wp-content/uploads/2013/06...
or this, if you wanted a dress:
http://juegoskizi2.com/wp-content/uploads/2014/04/skirt-suit...
I do not thing most women would have an issue about assuming they aren't a programmer (any more than a man in a suit) wearing either of those two last things I linked.
You might say that it's loudly styled, but somehow this guy never has people doubting his programming cred: https://www.google.com/search?site=&tbm=isch&source=hp&biw=1...
You might say that it's loudly styled, but somehow this guy never has people doubting his programming cred: https://www.google.com/search?site=&tbm=isch&source=hp&biw=1...