How can you convince your little sister that Santa Claus is real?

if she doesnt believe in santa or is doubting, tell her that he is real because you saw him!

you can even make "santa prints" in the snow. write a letter to him asking for a 'REPLY' from santa when a letter comes tell her that you told her so!

ask her things like: how would all of the presents be there? didnt you hear him last night? whered the cookies go?