From Wikipedia:
A finishing school (or charm school) is “a private school for girls that emphasises training in cultural and social activities.”[1][2] The name reflects that it follows an ordinary school and is intended to complete the educational experience, with classes primarily on etiquette. It may consist of an intensive course, or a one-year programme.
The term finishing school is occasionally used in American parlance to refer to certain small women’s colleges, primarily on the East Coast, that were known for serving to prepare their female students for marriage. Since the 1960s, many of these schools have become defunct as a result of financial difficulties stemming from parents’ decreased interest in paying for such an education for their daughters, and changing societal norms making it easier for daughters to pursue academic and professional paths not open to previous generations.
Sounds like seminary to me.