The feminine Spanish noun identifying the celebrated girl or young woman is quinceañera.
The term comes from quince años, meaning “fifteen years,” and is formed as a feminine noun. In common usage, quinceañera can also refer to the entire birthday celebration, not only the person at its center.
The masculine counterpart is quinceañero. That distinction matters because some families and communities hold comparable 15th-birthday celebrations for boys, while the feminine form has become much more strongly associated with the traditional ceremony.
A quinceañera is not the same as a dama or madrina. A dama is traditionally a female member of the court, while a madrina is a sponsor or godmother-like supporter in some celebrations. Terminology and roles vary, so these labels should not be treated as universal requirements.