In Xinchu Erlang Pishan Jiumu Quanduan (新出二郎劈山救母全段), a Qing dynasty folk storytelling manuscript,she is said to be the second daughter of the Jade Emperor.
[1] However, in the Fengshen Yanyi novel and subsequent adaptations, she is just a normal human woman.
She is called Lady Suzhi (素知夫人) in the Ming dynasty religious book The Collection of Gods in Three Religions [zh].
One day when she was sleeping, she dreamed that a deity Taiyi Zhenren put something into her arms; she woke up with pain in her abdomen and gave birth to a meat ball in the incense chamber.
With a round like a wheel, Li Jing slashed at the meat ball with a sharp sword, and jumped out a child.