How do i get my sister to stop taking my things?

I'm literally fed up with her, she takes all my stuff. plus when my mum buys us something and i choose one thing, she wants the same thing as me. She used to even take my shoes ( now i hate anyone touching my shoes!) but now the good thing is she's gt a bigger size feet than me and that's the only thing stopping her from wearing my shoes. However, she still takes my headscarves, top, cardigans, literally anything of mine that she can get her hands on. ( i wanna strangle her!) how do i make her stop...telling her is not working.