For Sedgwick, try Hope Leslie -- it was written in response to Last of the Mohicans, which Sedgwick found overly sexist and racist. It's a frontier romance with the topic of female participation in the New Republic at its heart.Hope Leslie
is fantastic. I should reread it.
My favorite Alcott stories are the ones that don't feature the March children. You might try the collection that Madeleine Stern edited -- fans of Little Women are often surprised by the sexiness of Alcott's gothic stories. I'd imagine Behind a Mask is the most famous of these now.
my favorite Alcott novel. (It's not gothic, though.)