An Etymological Dictionary of the German Language/Jungfer
ModHG. Jungfer, f., ‘young girl, virgin, maid, maiden,’ is developed from MidHG. juncwrouwe, ‘noble maiden, young lady’ (thus, even in MidHG., ver appears for the unaccented proclitic Frau). To this is allied Junker, m., ‘young nobleman, squire’ (prop. ‘son of a duke or count’), from MidHG. junc-hē̆rre, ‘young lord, noble youth’; corresponding to Du. jonker, jonkheer, whence E. younker is borrowed.