Letter published in Teen Titans v1. #26 (March-April 1970)
...and Dick Giordano's answer (not withstanding his comment about his cute li'l secretary) is a pretty diplomatic and believable reason why Ms. Troy wouldn't wear a miniskirt...because it would be a bit of a problem (ahem) to fight in. Not that that has stopped DC from putting Supergirl in a miniskirt for the past many, many years. And anyway, take a look at the cover of that same issue, Teen Titans #26, and see where your eye is drawn:
Cover of Teen Titans v1. #26 (March-April 1970), pencils and inks by Nick Cardy
Don't worry, Ed Shea of Plainville, Connecticut...Nick Cardy's got you covered where you want.
Of course, that must mean the Titans themselves are models of polite, non-sexist, proto-feminist behavior, right?
Panel from Teen Titans #25 (January-February 1970), script by Bob Kanigher, pencils and inks by Nick Cardy, letters by John Costanza
Now, before we all get ourselves in an uproar, I don't think you can say anything worse about this issue than "Boy, Nick Cardy sure liked to draw pretty girls, didn't he!" After all, he even proves in issue #30 that the female Titans can kick-ass with the best of them...even in miniskirts:
Page from Teen Titans #30 (XXX), script by Steve Skeates, pencils and inks by Nick Cardy, letters:by John Costanza
There you go. After all, it's not like the book is making miniskirts its specific focus, now, is it?
Panel from Teen Titans #25
Oh for cryin' out loud.