In a quinceañera, the girl celebrating her fifteenth birthday is commonly called the quinceañera.
The same word is also used for the celebration itself, so context matters. In English-language usage, “the quinceañera” can mean the young woman, the party, or the overall tradition. Spanish grammar gives the feminine form to a female celebrant; a masculine adaptation, quinceañero, is used in some communities for a boy’s fifteenth-birthday celebration.
The term is related to quince años, meaning “fifteen years.” It therefore identifies the age milestone rather than a specific dress, dance, religious service, or party venue.
A dama is an attendant, a chambelán is commonly a male attendant, and a madrina is a sponsor or godmother. Those terms describe other participants and should not be substituted for the name of the celebrant.