Updated

With her head lowered and holding her public defender's hand, a young mother accused of dropping her three sons into San Francisco Bay (search) pleaded innocent to three counts of murder.

After a brief arraignment Friday, 23-year-old Lashuan Harris (search) — whom family members have said suffers from schizophrenia — was returned to a hospital jail ward where she is under suicide watch.

Harris quietly answered "yes" when the San Francisco Superior Court judge asked if she was willing to waive her right to a speedy preliminary hearing.

Harris' lawyer, Teresa Caffese (search), refused to comment on her client's mental state or whether she planned to invoke an insanity defense. Harris was held without bail in a jail ward at San Francisco General Hospital.

"It's a tragedy for the families, the babies and Ms. Harris. This is a very, very difficult time," Caffese said outside court. "This can't be captured in words right now."

Authorities said Harris, a former nurse's assistant who was living in a homeless shelter with her children, was seen lifting her three boys over the railing of a downtown pier on Wednesday. The body of her middle son, Taronta Greeley, 2, was recovered late that night about two miles from Pier 7.

The other two boys — Treyshun Harris, 6 and Joshoa Greeley, 16 months — remained missing Friday, but were presumed dead.

Harris, who was arrested after police spotted her walking a bay stroller away from the crime scene, faces three counts of murder with the "special circumstance" of multiple murder.

A claim of special circumstances means a murder defendant could be eligible for the death penalty, but San Francisco District Attorney Kamala Harris said she had not yet decided on whether to seek such a sentence.

"I've also said I'll always review the facts and compare them to the law before I announce my decision," the district attorney said outside court.

The San Francisco Medical Examiner confirmed that the body that surfaced belonged to Taronta Greeley and completed an autopsy but was not expected to release a cause of death until Monday.

The U.S. Coast Guard (search) called off its search for the bodies of the other missing boys, but the San Francisco police and fire departments continued to scour the bay.

Harris told investigators she had stopped taking the anti-psychotic drug Haldol once she got her schizophrenia symptoms under control over the summer.

But the voices returned Tuesday night and were with her when she dropped her children into the water, police documents show.

Ron Honberg, legal director for the National Alliance for the Mentally Ill, said Harris would most likely undergo a hearing in the months ahead to determine if she was mentally competent to stand trial.

But even with her psychiatric history, which included at least two hospitalizations this year, she would likely face a tough time persuading a jury that she was not criminally responsible for the deaths of her children, Honberg said.

"There is a lot of cynicism about whether people charged with this crime should be found criminally culpable," he said. "People understand better if a person has an IQ of 50 than if a person has an IQ of 150 but may be profoundly ill."

Family members said Harris had made threats concerning her children before. An aunt told the San Francisco Chronicle that Harris' deteriorating mental state over the last few months prompted the woman's mother to contact authorities, but others said they did not think Harris would actually kill her children.

"She told my mama she was going to feed them to the sharks," said Britney Fitzpatrick, Harris' 16-year-old half sister. "No one thought it was that serious."

Sylvia Soublet, a spokeswoman for the Alameda County Social Services Agency, told the Chronicle she could not discuss whether the family had contacted her agency about gaining custody.

"Lashuan is very protective of the children and I think one of the reasons Lashuan stopped taking her medication was for fear of losing her three children," an uncle, Avery Garrett, told NBC's "Today" show Friday.