Who is Beloved?

When first reading about Beloved's entrance into the book, a lot of questions popped into my head. At first, I thought she was just a slave that got the chance to run away, but as the text continued I became more and more curious. Eventually, I started to develop theories on who she could be, or what she could be. My first guest was that she was some type of ghost that had to do with the river. I thought this primarily because she came from the river, but I supported this idea after learning about her knowledge of the diamond earrings. I was very confused when Beloved suggested she already knew about the earings. Then I remembered that Sethe gave birth to Denver in a canoe in the river. These events could be linked by suggesting that Sethe had the earrings on her when she gave birth and they fell into the river, which is how Beloved knows about them. Although while reading the scene in which Denver notices a mark on beloved my perspective changed. I began to think that Beloved is Sethe's mother. This would make sense because Sethe remarks that the main way she told her mother apart was by a burn mark she had on her torso. Overall, I cannot confidently say I know who Beloved is, but I am curious to find out if I was right.