The 38-year-old wife, and mother of two other children, is now facing felony charges.
"This baby was thrown in dumpster and left to die. It was treated like a piece of trash. And this is a baby girl just a few hours old," said Orange County District Attorney Spokesperson Farrah Emami.
Authorities say Sepulveda's 11-year-old daughter discovered the baby girl in the trash bin. She immediately told some adults who took the baby to get help.
"All of the evidence we have shows that this baby belongs to Ms. Sepulveda," said Emami.
Sepulveda's attorney says the she has no criminal history. The attorney also says Sepulveda was described by her family as a loving mother.
"She's been very involved in their lives up to date. And best description I've heard from the family is that she's been a doting soccer mother," said Defense Attorney Jake Brower. "They're shocked by this. And, so, they searched themselves for some sort of explanation. They know her not to be this sort of person who would do the things being alleged," said Defense Attorney Jake Brower.
"We're not speaking to a motive right now. All I can tell you is that she has been charged with attempted murder and child abuse," said Emami.
In court, Sepulveda showed no emotion, but her Brower says she's been very upset. Her attorney also says Sepulveda wants her two other children to know she loves and misses them.
"Super distraught, crying, just very upset ... over the whole situation ... the baby especially," said Brower.
The baby Sepulveda allegedly left in the trash bin is in the hospital recovering, and she is expected to survive. The child will likely be placed in protective custody when she is released from the hospital.
Sepulveda's 11-year-old and 14-year-old siblings are in their father's custody.