A collection of 3D vocal tract shapes corresponding to vowels and consonants of American English have been acquired for a 27 year old adult female subject using a magnetic resonance imaging. Each 3D shape was condensed into a set of cross-sectional areas of oblique sections perpendicular to the centerline of the vocal tract's long axis. Such a collection of areas is typically called an 'area function'. This set of images and subsequent area functions for the female subject compliments a previous similar study concerning an adult male subject. It is the purpose of this paper to explore the morphological differences between the male and female subjects for three 'cardinal' vowels. Comparisons have been made of the 3D vocal tract shapes, area functions, and acoustic characteristics of the three vowels. The primary difference between genders is that the female pharynx is approximately 37 percent shorter than the male. Limited acoustic modeling has suggested that this shortened pharynx may play a significant role in defining male versus female voice quality.