She's the reason why they love her so. An attractive mate or girlfriend.
A wretched skank who also happens to be an idiot sans the savant. Term popularized by the comedic writings of Adam Reed/ Archer
1940's term, back when young women wore poodle skirts and rolled their bobby socks down to their ankles. Shirley Temple portrayed this adorable, adolescent character in 1947 Oscar winning film; The Batchelor and the Bobby Soxer.