Los Angeles mother charged with killing her three kids

Relatives, including Sandra Chico's younger sister, said the mother-of-three had been struggling with postpartum depression. Photo / Supplied

An East Los Angeles woman was charged Wednesday with killing her three children, including a baby, earlier this week.

Sandra Chico, 28, appeared in court but a judge postponed until next month her arraignment on three counts each of murder and assault on a child causing death.

Her bail amount was raised from US$2 million to US$6 million.

Sandra Chico, 28, appeared in court but a judge postponed until next month her arraignment on three counts each of murder and assault on a child causing death. Photo / Supplied

"In an instant, three innocent children were taken from us and we are crestfallen," Los Angeles County District Attorney George Gascón said in a statement.

"Nothing is more heartbreaking than the tragic betrayal of a parent failing to protect their children."

The children were found dead in a bedroom of their home on Monday.

Authorities have said there were no obvious signs of trauma and authorities hadn't been called to the home by any previous indications of trouble.

The prosecution statement didn't specify the cause of death. However, family members have said Chico suffered from depression and that she suffocated them and then tried to kill herself, KABC-TV reported.Chico was initially detained, and authorities announced her arrest on Tuesday.

The coroner's office identified the children as Mia Camila Rodriguez, 4, and her brothers Mason Mateo Rodriguez, 3, and Milan Mateas Rodriguez, who was 1 month old.