Lucy Weasley was the younger daughter of Percy and Audrey Weasley. She has an elder sister, Molly, named after the girls' paternal grandmother of the same name. She possibly was attending, seeing her sister off to Hogwarts.
Lucy is of Latin origin and it's meaning is "light". Feminine form of Lucius; vernacular form of Lucia. The feast day of Saint Lucy (fourth century), patroness of sight, is called the Festival of Light in Sweden. Lucy can also be short for Lucille.