Just like the men, the frock coat symbolized the Captain's position fer all to see. You can wear a skirt or breeches as a captain. As you know a women can have many different outfits, even portraying the same character, it depends if ye be at the local tavern or the Governor's mansion.
The common wench n' a lady pirate both wear the same blouse, boned corset n' petticoat, the difference be that a lady pirate wears a pirate hat n' weapons. How ye be wearing the clothes determines yar purpose: sexy (modern) or proper (historical).
The traditional look be with long petticoat under a over skirt. The modern look be with only one shorter skirt to show off a knee, how scandalous! Both wear the real steel boned corset or bodice to give that hour glass shape.
A common wench normally doesn't wear a steel boned corset, weapons or a pirate hat. These outfit arrr more comfortable to wear n' more affordable to yar dubloom purse. Great looks to start out, which ye can later upgrade.