Gender Identity: Cis woman
Uhura sees herself as a woman and her identity as a woman is integral to her self-image. She would be extremely uncomfortable in a man's body or even simply misgendered as a man.
Sexual Identity: Heterosexual with an open mind
She is a firm believer in the fluidity of sexuality, but she has yet to be sexually attracted to a woman.
Romantic Identity: Heteromantic with an open heart
In the school of "anything's possible," Uhura won't write off the idea of a romantic relationship with a woman, but it's not very likely to happen. Everyone she's ever fallen in love with has been a man.