The traditional quinceañera celebrant is female.
Quinceañera is the feminine Spanish term used for a girl celebrating her fifteenth birthday. The custom historically developed around a public transition for young women, which is why traditional descriptions use feminine language and symbols.
The masculine form quinceañero exists, and some families and communities have adapted the celebration for boys or for more than one celebrant. Those modern variations do not change the traditional gender association of the word quinceañera.
Gender expectations surrounding the event have also changed over time. Contemporary celebrations may use different clothing, dance arrangements, attendants, and themes from older models. It is therefore useful to distinguish the historical convention from the many ways families now personalize the occasion.