Nancy Blake in love with Sylvia?
I think Nancy is attracted to Sylvia because she is always bothering her, and she haven't no interest in the other girls.
But there are one thing that really impressed me: The scene in which Silvia took off his coat, Nancy saw her breasts and said, "Good Guns"
I do not know if it was common at that time look in that way a friend, and say the equivalent of "you have nice tits."
Nancy is considered different from others, not a woman or a female (Because a woman and females likes men). She is "What nature abhors" ... Now, at this point I don't think so "old maid" was unnatural. They were ridiculed, and people laugh at them, but nobody see them as unnatural. I think Nancy means that she is a lesbian, a woman who does not like men
I think Nancy's lesbianism is very marked in the film, as her obsession with Sylvia