I was curious to know more about Miss Kotter but couldn't find any other information about her -- not even her first name (she signed letters "A. Kotter").
But now, thanks to some spectacular sleuthing by volunteer researcher Catherine Bloomquist, I know quite a bit about Miss Kotter. Her first name was Althea and she had two marriages (one of which ended in a Reno divorce -- classic!). That's her at the top of this entry, although her name was Althea Borden by the time that photograph was taken.
Interestingly, it turns out that Miss Kotter (which is how I'll always think of her, even though I now know her full name) was relatively young when she worked at Manhattan Trade. She was born in 1906, which means she was in her mid-20s when she was recording most of that stern feedback in the students' files -- not all that much older than the students themselves. I had pictured someone in her 40s or 50s. She obviously took her job very, very seriously.
Miss Kotter died in 1971, but I spoke yesterday with her niece, a retired newspaper editor who lives in North Carolina. She had no idea that her aunt had once worked at a school. She said Miss Kotter later went on to run the personnel office of a business -- a natural-seeming progression from her position in Manhattan Trade's job placement office.
Also: Miss Kotter had a son who's still alive. The niece is getting in touch with him to see if he'd be willing to speak with me for a future article. Fingers crossed.