This is a quote by Beloved “Three times I lost her: once with the flowers because of the noisy clouds of smoke; once when she went into the sea instead of smiling at me; once under the bridge when I went in to join her and she came toward me but did not smile. She whispered to me, chewed me, and swam away. Now I have found her in this house. She smiles at me and it is my own face smiling. I will not lose her again. She is mine.” This basically is saying that how she has lost her mother 3 times and as we have seen she only gets lost one by Sethe. Now if we think of Beloved being reincarnated and that she took birth again then it may have been that she had death before. It can also possibly mean that she had a life before which she lost and it was counted to be 3 times including when she was lost by Sethe.
She clearly says in the quote that once with the flowers which I could not make sense to and once under the bridge and once into the sea, which I am sure this is what is described in the book when Sethe had decided to send her children away and join them later at sea.
Also the author might just try to hint on history repeats itself and so Beloved had many same experiences that were constantly repeated. This can go both ways as it also can just be understood that there was past life too.
