Girlhood is the time in a female person’s life when she is a girl — childhood and the years of growing up, before she is thought of as a woman. People use it in stories and memory: “in her girlhood,” “a girlhood friend,” “girlhood summers.” It can mean the years themselves, or the feeling of that time. It is a little literary or nostalgic; in everyday talk someone is more likely to say “when I was a girl” or “when I was little.” It is not a medical stage with a clear end date — different families and times draw that line differently.