Devorah Haneviah was the only woman was was a Judge and had neviah, and the Gemorah discusses this and answers include that it was an extreme case and she was given permission by Hashem, and that she advised male judges.
Also, the Gemora in Kesuvos states that certain people who are on very high madreigos are allowed to act in ways that for normal people would be considered not tzniusdik, because to them, the woman (the Gemora is talking about a man) is not a taavah. You can be sure that the men were not looking at Devorah at the time – for all we know there was a seperation between them or she was off to the side or something else, but you can be sure that the circumstances were set up so as to facilitate tznius.