My friend is very clingy?

i have this friend called *maggie and she is so clingy, she isn't my best friend and im not her best friend her best friend and go round in a twosome but hang around with me and my friends alo because we are good friends. maggie is getting way to weird, she always calls me name i turn around and she smiles and says hi two minuites later she does it again, and my best friend has noticed it too, how she always stands right in my face and if i move back a bit she moves closer too me again and i move back and she moves closer also, she always needs to touch me somehow, like a hug or grab hold of me hand and pull me along if i don't follow her when she wants me too. and my best friend said she has seen her stare at me often, and when we were changing for P.E she was staring at me again. its getting a bit too creepy, what can i do without being mean too her?