She is Luffy's twin sister.
She goes blind at the age of seven, trying to save Sabo from the cannon fire.
She sails with Ace and Sabo, at the age of 14.
Sabo, Ace, and Gracy start the Spade Pirates.
She also told Luffy when they meet again she will join his crew.
Ace and her share the Flame-Flame Fruit.
Gracy finds a cat and names him Lami, he helps her with seeing.
Ace and Sabo join The Whitebeard Pirates, while Gracy just stays with them, till she meets with Luffy again.
She meets a strange guy (Law) at Sabaody with Luffy and his crew, and his personality and voice just pull her to him.