Quinceañera is the usual English term for the young woman celebrating the milestone.
In Spanish, the feminine noun identifies the celebrant, while the word can also be used informally in English for the party itself. The male counterpart is quinceañero. Because regional usage varies, speakers may use quince años or simply quinceañera to describe the event.
The term should not be confused with dama or chambelán. Those words refer to members of the court of honor, not to the central celebrant. The celebrant may be accompanied by attendants, but she remains the person whose 15th birthday is being marked.
Spelling and accents can vary in English-language writing, yet quinceañera is the standard Spanish form. The ñ is pronounced as the “ny” sound in Spanish words such as mañana.