JACKSONVILLE, Fla. -

The mother of Duval County's youngest murder defendant pleaded guilty Wednesday to the aggravated manslaughter charge she was facing in the death of her youngest son.

Biannela Susana, 26, was charged in connection with the death of 2-year-old David Galarriao just over a year ago. Her oldest son, Cristian Fernandez, now 13, is accused of killing David, his half brother. Prosecutors believe Fernandez slammed the boy's head into a bookshelf while they were home alone.

According to Susana's arrest report, when she returned and found the toddler unconscious, she wiped blood off his face, changed his clothes and put ice on his head, hoping it was just a concussion and the boy would wake up.

Police said she waited two hours before driving David to St. Luke's Hospital. Police records show she may have spent time searching for information about concussions on her home computer.

Doctors told police that if she had sought immediate medical treatment, the boy may have survived.

"This case involves Ms. Susana's negligence in both allowing that injury to occur by lack of appropriate supervision of her children ... also her failure to act in an appropriate manner once she was made aware of the injury inflicted upon David Galarriao," Assistant State Attorney Mark Caliel said. "There was an omission in open court today that she did delay in seeking medical attention for her child. That was one of the factors, the factual basis, for her plea."

During Wednesday's hearing, Susana told Judge James Daniel that accepting a plea agreement that would require that she serve a minimum of 13 years and a maximum of 30 years in prison was in her best interest.

Susana is expected to be sentenced within 60 days.

"She's doing well. I think she is," Susana's defense attorney, Shawn Arnold, said. "Obviously, she's very heartbroken over what happened. She lost a child in all of this and has lost the rights to her children going forward, so obviously she's distraught about that, and that's what her focus is on. She's very worried about what's going to happen to Cristian."

The next hearing in the Fernandez case is set for April 19, but a date for his first-degree murder trial has not been scheduled.

Asked how the resolution of Susana's case might affect the case against Fernandez, prosecutors said they could not comment.

Because of the nature of the ongoing criminal prosecution of Christian Fernandez, Caliel said, "It's really inappropriate for me to comment specifically on facts and circumstances."

Hank Coxe, the attorney representing Fernandez, was in the courtroom Wednesday. It's unclear how Susana's guilty plea will effect the case against her son.

Coxe released this statement Wednesday:

"The person who admitted responsibility for the death of her 2-year old son, David, pleaded guilty to manslaughter. Apparently the doctors who treated David said he would have survived if he had received medical care sooner. Instead, his own mother waited for eight hours to seek medical attention causing the death of her son. Her 13-year-old son, Cristian, continues to face adult first-degree murder charges, which carries a mandatory life sentence, yet his mother pleads guilty to a much lesser charge. We will deal with this in the courtroom."

Richard Kuritz, a defense attorney not associated with either case, believes that Fernandez's case could also end in a plea.

"I don't know if it has an impact on what might happen with the son, or if it's an indication that the cases are starting to wrap themselves up," Kuritz said. "The defense team -- the new defense team -- has been on the case now for well over a month now, so there's a good chance that what we're seeing here is the beginning of the end."