FAIRFIELD — A prosecutor’s proposal to dismiss a manslaughter charge against a 12-year-old girl in connection with the death of a 3-month-old nearly two years ago as part of a plea agreement is not sitting well with the infant’s mother.

The Fairfield girl, whom the Bangor Daily News is not naming because she is a juvenile, was 10 years old when charged with reckless or criminally negligent manslaughter in the death of Brooklyn Foss-Greenaway on July 8, 2012.

Brooklyn’s mother, Nicole Foss-Greenaway of Clinton, is upset with the plea agreement and expressed her concerns to Assistant Attorney General William Stokes on Wednesday when he contacted her to give her the details, she posted on her Facebook page.

The girl — the youngest in the state to face a manslaughter charge in recent history — will be charged with a misdemeanor and be subject to long-term supervision and counseling in exchange for dismissal of the felony charge, Stokes said Thursday.

“I don’t know what to think or what to do or what to say,” Greenaway wrote, having given the Bangor Daily News permission Thursday to reprint her Facebook statement. “My heart feels like all the broken pieces have broken into more pieces. I don’t think I can ever get put back together.”

She said she “flooded” Stokes with questions.

“Did I like all the answers? NO I DID NOT,” the baby’s grieving mother posted. “Is there anything I can do about it? NOPE THERE IS NOT! I am so [expletive angry].”

Greenaway said she will be at the courthouse next week when the girl goes before a judge regarding the proposed plea agreement.

“The top goal was always to get this girl the treatment and counseling she needs,” said Stokes, who leads the criminal investigative division of the attorney general’s office. “The idea was never to incarcerate her.”

The girl made her initial appearance in Skowhegan District Court on Oct. 22, 2012, and was deemed not competent to stand trial for the felony charge in March 2013.

John Martin of Skowhegan is the girl’s attorney. A message seeking comment from Martin on Thursday was not returned.

The girl is scheduled to appear Wednesday, May 21, in a closed-door hearing at Somerset County Superior Court in Skowhegan to determine whether she is legally competent to stand trial, Stokes said.

“She will admit, enter pleas to a lesser charge and the result of that is she will be in long-term supervision for a substantial number of years,” the assistant attorney general said of the plea agreement.

In the plea agreement, which still needs court approval to become final, the girl will admit to committing a misdemeanor, he said. Juvenile laws prevent him from saying exactly what crime she will admit to committing.

The baby was in the care of the girl’s mother in Fairfield on the night she died. According to Greenaway, her infant was left alone with the then-10-year-old girl.

Greenaway said in August 2012 that a toxicology report revealed that medicine for attention deficit disorder was found in Brooklyn’s system. She said it was the same medication prescribed to the accused girl. There also were bruises on the baby’s face from when she was suffocated, allegedly by the girl, according to Greenaway.

“It looks like someone had beat her up,” Greenaway said shortly after her child’s death. “Fingerprint bruises all over her face. A black eye. Bruises across the bridge of her nose.”

Greenaway declined a request for an in-person interview on Thursday.

The girl has been in the custody of the Department of Health and Human Services since she was charged with manslaughter.

If convicted of manslaughter in the juvenile system, the girl would have been in state custody until she was 21.

Weeks before Brooklyn’s death, another baby overdosed on medication in the home of the same Fairfield baby sitter.

Ashley Tenney, mother of the 8-month-old baby, who survived, told the BDN in September 2012 that doctors told her they had found amphetamines in her daughter’s system that matched medication prescribed to the girl for attention deficit disorder.

Brooklyn’s death was declared a homicide on Aug. 29, 2012, and the girl was charged with manslaughter the next day. On Sept. 19, 2012, the attorney general’s office filed a juvenile petition formally charging the girl with manslaughter.

“We couldn’t do nothing. You couldn’t just ignore this. You had to recognize this for what it was,” Stokes said, explaining the state’s actions Thursday. “The juvenile code is there to sort of [allow prosecutors, judges and attorneys to be] creative when dealing with young offenders who we want to become productive members of society.

“That is the goal. That is why we utilize the juvenile code in the first place,” he said. “This way involves the juvenile and holds her accountable. Under this is the condition you have to take responsibility for [the actions] but at the same time can move in the direction of treatment, counseling, supervision and rehabilitation.”