Natalie is a female but feels most comfortable wearing men's clothes. She strongly wishes to be a man and is considering a surgical procedure to remove her breasts and make her body appear and feel more male. The MOST likely diagnosis for Natalie is gender:
Gender dysphoria is a condition where a person experiences discomfort or distress because there's a mismatch between their biological sex and gender identity. It's sometimes known as gender incongruence. Source: national health service
If she feels she wants to be a male but isn't one entirely yet, she is Trans-Male. She will be going through the procedure to become a male, So she would most likely like to be called a male.