Of course there's Therese, the well-developed protagonist of The Price of Salt (aka Carol), a lesbian romance. This work and its movie adaptation are the reason she's a gay icon - both are popular and well-loved.
Highsmith published The Price of Salt under a pseudonym after her success with "Strangers on a Train", which is driven by the masculine characters you mention. From what I can tell, The Price of Salt is more directly based on her personal life, or rather her fantasies, and part of the reason she used a pseudonym is that her agent warned her that writing a lesbian novel would be career suicide. Wikipedia has more here: https://en.wikipedia.org/wiki/The_Price_of_Salt "Highsmith described the character of Therese as having come "from my own bones"."