Sepulveda gave birth in August of 2008 in the bathtub of her apartment, where she lived with her husband and their two children.
According to prosecutors, the 39-year-old Laguna Niguel mother kept her pregnancy a secret, because a man that was not her husband was the father.
According to police testimony, Sepulveda cut the umbilical cord with a steak knife from her kitchen and took the infant to a trash bin in her apartment complex.
Sepulveda's other daughter discovered the baby in a trash bin later that day. The baby was taken to a hospital and brought into protective custody.
Sepulveda faces up to life in state prison at her Sept. 24 sentencing.
AP and CNS contributed to this report.
