She wears her hair curly for special occasions.

wears 是动词 wear 的第三人称单数现在式，wear 的基本意思是"穿着、佩戴"，在这里引申为"保持某种发型或发式"。 wear one's hair + 形容词 表示"保持某种发型"，比如 wear one's hair long（留长发）、wear one's hair straight（保持直发）等。