My 4 year old daughter refuses to sleep in her room with out me!

My daughter is 4 years old, she hates sleeping in her bed alone, with out me! She is always asking me to lay down with her until shes a sleep, and once she is finally a sleep I leave the room, sometimes she sleeps all night, but most of the times I wake up with her next to me in my bed. I have tried buying her things to make her more comfortable.. for example, buying her a new night light, a new baby doll or stuffed animal, reading her a book or 2 or 3 before bed, i even bought her a Queen size bed to make her feel like a "big girl who sleeps in her room all by herself, just like all the other boys and girls she will meet when she stats school!" Does anyone have any ideas that might help us out a little bit? Thanks a bunch!!