The arraignment for a California mom accused of pushing her 7-month-old baby to his death from a parking structure was postponed on Thursday after a doctor found her mentally unfit to go to court.

A doctor who examined Sonia Hermosillo, 31, in the hospital ward of the Orange County Jail placed her on a medical hold after determining she could pose a danger to herself, Orange County Sheriff's spokesman Jim Amormino told Reuters.

In the opinion of the medical staff, she was in no mental condition to attend court today, Amormino said, adding that Hermosillo was under 24-hour suicide watch and getting proper care for her psychological issues.

Hermosillo was charged on Wednesday with murder and assault on a child. She was being held on $1 million bond and was also subject to a U.S. Customs and Immigration Enforcement hold while authorities determine if she is in the country legally.

Prosecutors say Hermosillo pushed her 7-month-old son some 40 feet on Monday from a parking garage at Children's Hospital of Orange County, where the boy had been treated for birth defects. He died from his injuries on Wednesday.

Hermosillo's arraignment was rescheduled for Monday on the charges, which carry a maximum sentence of 25 years to life in prison. Amormino said it could be delayed again if doctors find she remains mentally unfit.

Her husband, Noe Medina, has told reporters his wife suffered from severe postpartum depression and had trouble accepting her son because of his health problems. The couple have two other children.

She didn't know what she was doing, Medina told reporters through an interpreter on Wednesday. Please don't judge her.

Orange County Deputy District Attorney Scott Simmons told Reuters he expected the defense to raise the psychological issues at trial. But he said it would not be enough to prove Hermosillo suffered from postpartum depression.

There are a lot of facts that establish she knew what she was doing, he said.

Simmons said evidence would show that after pushing her baby to his death, Hermosillo went inside the hospital to validate her parking before fleeing the scene.

Her attorney, public defender Chuck Hasse, could not be reached for comment.

A witness who saw the boy falling through the air called 911 and Hermosillo was taken into custody after police spotted her car, which had been captured on a surveillance camera at the parking structure.