When do you become a woman? As in, someone that your friend or colleague actually refers to as a “woman.” It is is certainly not after your Bat Mitzvah (will get back to that later), nor is it when you graduate from high school, or even college.
Today, the age of a woman who most of us feel comfortable calling a “woman” is being pushed further and further back; I personally hesitate or feel awkward using the term for anyone under 45. The issue is, many of us also feel the same about using “girl” for anyone over 25, and even that feels a little iffy. So basically for approximately 20 years there seems to be no appropriate term to describe people with vaginas.
Women long for an analog to “guy,” something that messages mature but not stuffy. “Gal” would technically fit the bill, but it hasn’t made much traction.