Skirts and stuff are difficult, and the traditional look maybe isn't easy to do with one of the long-dress models, because the shape of the top may be wrong. Posette, at least, there do some to be some dresses with a more plausible top. Look for terms like "peasant" and "country". And it may not be too hard to combine two dresses, top of one and bottom of the other, by turning components invisible. I know a little about medieval clothes, via friends who are into the SCA and more serious reenactment, and rather a lot of stuff out there is a bit too much Hollywood-fantastic, for modern actresses wearing modern undergarments.