Maid Marian is a vixen (a female fox), and is a noble lady of England, born a niece of King Richard (though she is not Prince John's daughter).  Being a high-born lady, she has been schooled in the noble and genteel arts, including etiquette, protocol and the spoken word.  She is attended, and protected, by Lady Kluck, her lady-in-waiting.

Maid Marian left Nottingham, her ancestral home, when she was a child, spending many years in London learning the finer points of being a member of the nobility.  She knew Robin Hood when they were both children (when they shared a more innocent and youthful affection for each other), but lost touch with him upon leaving for London.  Upon her return to her family estate in Nottingham, and during her uncle Richard's absence (as a result of his participation in the Crusades), she had to walk a fine line so as not to upset Prince John, all while hoping and dreaming that she would see Robin again, and that they would renew their romance.  Which, of course, they eventually did, marrying and setting off on their honeymoon at the end of the movie.

Origins of the character: Maid Marian, as stated in The Robin Hood Project, by the Robbins Library of the University of Rochester (New York):

"...often given the containing sobriquet 'Maid,' is both an intermittent and elusive figure in the Robin Hood myth. She does not appear in the late medieval yeoman ballads or, with one exception, their seventeenth and eighteenth century broadside ballad descendants. She is an initial presence in sixteenth and seventeenth century gentrification, is less certain of a place on the eighteenth century stage, but becomes from the nineteenth century on a fixture as Robin Hood's partner, often wife, occasionally mother of his child or even children. She plays a usually substantial role in film, and has recently come to the fore in broadly feminist reworkings of the myth. Even when she is recurrently present, substantial variation has occurred in her activities and meaning, and it may be her complexity takes her back before the early outlaw ballads to the medieval French pastourelle tradition."

The statement of her becoming, in more recent film and literary adaptations, a more "feminist" character is indicative of the current era, rather than the medieval and renaissance foundations of the character (and pretty much all female characters).  Traditionally, she was cast as a genteel lady, not as a female warrior who would go toe-to-toe with the male characters.  Among the noblest aspects of the Robin Hood legends would be the protection of the damsel in distress by the brave male hero...of honoring her by traditional male risk-taking and sacrifice, rather than needing to watch himself around her and behave by some 20th or 21st century standard, which is anathema to the character and the legends.