A woman who drove her minivan into the Atlantic Ocean with her children inside in March has been deemed not guilty by reason of insanity by a Volusia County court judge.

Ebony Wilkerson, 33, was 28 weeks pregnant when she loaded her three children into a minivan and tried to kill them off the coast of Daytona Beach. A hearing will determine whether she will be hospitalised or freed under court supervision.

Wilkerson, called the "Minivan mom" in the media, waived her right to a trial by jury, and faced three counts of second degree murder.

Police in Myrtle Beach, South Carolina reported that Wilkerson accused her husband, Lutful Ronjon, of rape ahead of the attempted killing. She travelled to Florida with the children to stay with her sister, who called 911 when Wilkerson began talking about Jesus and demons.

According to police, the wife and mother was not detained because she did not appear to be a threat to herself or others. Nearly two hours later, she drove her minivan into the ocean with children aged 10, nine, and three years old inside. Lifeguards and passersby rescued the children and Wilkerson from the locked car.

Police reported that the children repeatedly told them "Mom tried to kill us," and that she brought them to the beach so they could die.

Wilkerson told Circuit Judge Leah Case that she is back to her "normal self" and on prescription medication. She is not permitted to see her children, and a hearing next week will determine if she will remain in custody or be released.

The three oldest children are in foster care in Florida, and the youngest child, who was born in prison, is being raised by Ronjon.