Kind of a strange idea

A fantasy world where dragons exist, except the traditional reptilian dragons are just the males.  The females look completely human, but have at least all the abilities the males do.

That or both hatch looking human and males go through a metamorphosis.

That's kind of already the D&D world, all dragons can shapeshift, and they mingle around humans constantly. That's why you have a significant population of people with draconic blood and strange powers

There's an anime called Cross Ange that has that very gimmick where there's a race of Dragons where the males are locked into giant dragon form all the time while females can shapeshift to a human form with just wings and a tail. They reproduce by the females returning to Dragon form. That said the dragons don't really factor and it's a god awful anime so don't watch it. There's no ubergirl or Dragon action to be had.

Suppose the female dragons in human form can mate with human men?  In fact, maybe that's how dragons reproduce - the offspring shape-shift into male or female dragons. 

A little bit of Species here

The female dragon rule over the human kingdom for over 1,000 years.