I created a girl named White D. Angel(Angi as her brothers were calling her when they were little).
She is Luffy's little sister. She's 2 years younger than Luffy. So when Luffy was 7 y.o. she was 4 y.o.
She originally came from an island known to the world as Hell Island. Because no ship can get to the shore of the island as the currents there are very rough and would destroy all ships who are unfortunate enough to get caught by the currents.
She ate Tenshi Tenshi no Mi and is an angel. It was given to her by her mother before she left.
The fruit is a Zoan type and its the strongest fruit in usage among all of other fruits for now. That'