What should I do with $1000 dollars?!?

My older sister bought me a scatch and win for $1 dollar just over a hour ago and I only just scatched it, but the thing is is that I was to only discove I won $1000 dollars! I'm only 14 through. My sister is normally selfish towards thing's and I'm affaid she will claim it's hers. What should I do?!! I'm having a complete happy hour right now and i'm still in shock! Thing's like this just don't ever happen to me, First time and I won $1000 that is alot for me :D