I would not say that Princeton actively recruits women in engineering any more than the university recruits men in a specific field. However, Princeton's reputation as a outstanding engineering program in a liberal arts university has attracted more women to the Princeton engineering school than most other universities. Many women are interested in combing an engineering education with the study of a foreign language, liberal arts, and the creative arts. Welcome - Lewis Center for the Arts
Women comprise 40% to 45% of the freshman engineering class.
The president of the university Shirley M. Tilghman, a noted scientist, has been a leader in promoting women studying STEM. See Princeton University - Tilghman presents rationale for more women in science and engineering
and Bridging the Gender Gap in Science and Technology -*Office of the President
. Tilghman has implemented programs such as child care and liberal pregnancy leave to attract female professors and mentoring/support programs for female engineers.
Take every ranking with a grain of salt. Look closely at the criteria used in the ranking. Many ranking systems use quantitative measures. The number of faculty, the number of academic papers published, etc. Large engineering schools have an obvious advantage in rankings based on quantity. Princeton engineering departments in chemical & biological, civil & environmental, computer science, electrical engineering, mechanical & aerospace, OR & financial engineering are all highly ranked. Because Princeton does not have departments in industrial engineering, petroleum engineering, nuclear engineering, material science, engineering management, or systems engineering some ranking systems will rank the Princeton engineering school lower than universities that offer more courses and have more faculty members. Princeton offers small classes taught by world renowned faculty.
In ranking systems based on quality indicators Princeton engineering is highly ranked. The Times Higher Education ranked Princeton third in the world. See Top 50 engineering & technology universities
Princeton engineering departments rank very high when the criteria is quality; for example when the number of academic citations is considered.
The National Research Council recently conducted the most comprehensive analysis of university academic departments. Follow this link to learn how Princeton academic departments were rated: Princeton and the 2010 National Research Council (NRC) Rankings (news item)
The president of Princeton, Shirley Tilghman, briefly discusses ranking systems in this article. Princeton Alumni Weekly: President's Page
At some universities students apply to the separate schools within the university; for example a student will apply to the business school, the engineering school, or the college of arts & sciences. If the student in the business school desires to study engineering the student has to apply again to the engineering school for admission. At Princeton all students apply to the university and can easily transfer to any department.