When she was alive, she neglected her baby girl to the point of death, before eventually passing away herself. In the afterlife, she became tormented by the cries of her daughter and a feeling of loss she did not understand.
The Avatar found the soul of the child in the Spirit Realm and brought her to her mother. Upon being reunited, Elizabeth realized how much she actually cared about her baby, and understood the true spirit of Love.
After this, Elizabeth finally found peace and vanished with her daughter after revealing to the Avatar that the Candle of Love could be found in the ruins of Empath Abbey.