Stephanie:  The only book I can think of that comes even remotely close to being "lesbian romance" is The Well of Loneliness, by Radclyffe Hall.  And I wouldn't call that infamous old book a 'romance'.  The author writes all around the subject of the book, intimacy between two women.  If you read it, you will need to recall how things were at the time it was written.   And for a counterpart to Annie Proulx's short story, Brokeback Mountain, I think such has yet to be written.