new fan-fic?

ok so i kind of want to start a new fan-fiction of course about one direction but i am not sure who i kind of have my plot down so the main character will be a sibling of one of the boys and she may or may not fall for one of the boys. now i don't want to give out too much because then it won't be interesting but here are some things that i need help on so fell free to comment what you think
1.) name for the girl
2.) who she is related to
3.) the boy you want her to fall for
ok so just comment your thought about this lol