The grandmother of a 3-year-old boy, who was found dead on a park swing as his mother pushed in May, is wondering why her daughter's mental health was not considered when she was indicted Monday on charges of manslaughter and first-degree child abuse. (WUSA9)

A 24-year-old mother who was found pushing her dead toddler on a swing in Southern Maryland has been indicted by a grand jury on charges of manslaughter and first-degree child abuse.

Romechia Simms, who was found with her 3-year-old son at a park in La Plata in May, was arrested Saturday and arraigned in Charles County Circuit Court on Monday.

At the arraignment, Simms objected when prosecutors declared her a danger and a flight risk, Kristen Ayers, a spokeswoman for the state’s attorney, told the Associated Press.

“I’m not a risk to anybody,” Simms said before her public defender advised her to be quiet. “I didn’t even mean for this to happen.”

She was being held on a $150,000 bond, authorities said, in a case that has generated headlines around the world. She could face up to 45 years in prison if convicted.

Romechia Simms is charged with manslaughter. (Charles County Sheriff's Office)

Charles County State’s Attorney Anthony Covington declined to say whether he thinks that Simms — who was hospitalized for a mental breakdown in the months leading up to Ji’Aire Donnell Lee’s death — intentionally killed her son.

“The way the system works here in Maryland, those mental issues can’t be taken into account until somebody is charged,” Covington said.

The medical examiner’s report, Covington noted, suggests that Ji’Aire was alive when he reached the park and died after 40 hours outside, including in the rain, without anything to drink. Authorities said they think that his mother may have been pushing him all night before a resident noticed how long they’d been there.

On Monday, his maternal grandmother, Vontasha Simms, said she was still grieving for Ji’Aire, a chubby-cheeked boy who was nicknamed “Sumo” and loved McDonald’s french fries and Dr. Seuss books. But she is also upset by the charges against her daughter. She described her as being in a “mental state” at the time of Ji’Aire’s death. Romechia Simms suffers from depression and bipolar disorder, her mother has said in the past.

“I feel like those are totally the wrong charges,” Vontasha Simms said in a phone interview. “I don’t understand how you’re going to charge someone who was mentally incompetent.”

She said she thinks that the charges were brought against her daughter months after the high-profile incident because “they had to do something” and were under a lot of public pressure.

Vontasha Simms, the mother of the woman found pushing her dead 3-year-old son on a swing in a Maryland park, talks about the last time she saw them and her theory on what may have caused the boy's death. (DeNeen Brown and Ashleigh Joplin/The Washington Post)

“This is uncaring and unfair,” she said. “They knew she would never do anything harmful to him to cause his death.”

Charles County District Public Defender Michael Beach declined to comment on the specifics of Simms’s case or whether her attorney would raise a mental health defense. He said his office is pushing for Simms’s release from jail because she is receiving mental health treatment and is able to live with relatives.

Ji’Aire’s father had sought custody in D.C. Superior Court just weeks before he died. James “Donnell” Lee told the court in his custody petition that he was worried about Simms’s mental stability after episodes of erratic behavior led to her hospitalization. But Simms argued in court documents that she’d recovered from her breakdown and was the more capable parent.

At a brief custody hearing May 11 before D.C. Superior Court Judge Peter A. Krauthamer, the parents agreed to share custody of Ji’Aire, with his father getting the boy on the weekends. Lee didn’t bring up Simms’s mental state or his fears about his son’s safety.

The mother and son were living with Vontasha Simms in a La Plata motel when sheriff’s deputies found the two in the park on May 22.

The swing where Ji’Aire was sitting had to be removed because police could not easily extricate the boy’s body from it. Charles County authorities ruled his death a homicide. He died of hypothermia and dehydration.

At the boy’s funeral in June, he was dressed in white and laid out in a white casket with a spray of white roses. Both his parents attended.

In the funeral program, Romechia Simms included a letter she had written to Ji’Aire: “Son, the joy you brought to my life is unexplainable. . . . I miss you so much, Ji’Aire, way more than I could possibly express through words. I am slowly accepting your passing. I want you to know that I have always been extremely proud of you, and I love you until the end of time. Ji’Aire Donnell Lee, you are amazing. Love always, Mommy.”

Keith L. Alexander, DeNeen L. Brown and Ian Shapira contributed to this report.