There is a way of being a full lesbian route still that means that doesnt mean that some man wont try still this involves some teasing like showing herself nake to her brother or others, but that isnt really considered an straight interaction at least not to the counter (In season 2 you have this counter) i think there is a scene at the end where she get touched by a guy in season 1 but i cant remember too well if it was avoidable, teasing guys is not avoidable most of the time since well you will see when you start it but yeah lyanna in the game express herself as a lesbian so yeah thats that