AUGUSTA, Maine — When Nicole Greenaway dropped off her 3-month-old daughter at the babysitter’s house in Fairfield on July 7, 2012, she left her child in the care of her then friend and co-worker, Amanda Huard.

Huard’s 10-year-old daughter, who is now 12, was later charged with manslaughter in the death of Greenaway’s daughter, Brooklyn Foss-Greenaway. The 3-month-old was drugged, suffocated and found unresponsive on the morning of July 8, 2012. The infant died at the hospital later in the day. The Bangor Daily News is not naming the girl because she is a juvenile.

The state dropped the manslaughter charge against the 12-year-old girl in May in exchange for guilty pleas to lesser charges, Assistant Attorney General William Stokes said at the time.

Nicole Greenaway, who lives in Waterville, has said from the start that she wanted charges brought against the girl’s mother and decided this week to file a 13-count lawsuit in Kennebec County Superior Court against Huard and her daughter for negligence.

“This case is the epitome of a family that needs to see justice,” attorney Sheldon Tepler of Lewiston, who is representing Greenaway, said Tuesday. “They need validation. There needs to be some way for their natural feeling of anger to get satisfied, and I see a civil lawsuit as a way to get that justice.”

The lawsuit focuses on multiple claims of negligence against Huard and her daughter, and it includes claims of suffering and emotional distress suffered by an older sister of Brooklyn who was in the same room when the assault took place. The lawsuit seeks unspecified financial damages.

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

John Martin of Skowhegan, who represented the girl, said he has not seen the lawsuit filed by Greenaway.

“Without having reviewed the complaint or discussing the matter with the department, I would not have a comment at this time,” he said in an email.

His client is in the care of the Department of Health and Human Services. Messages left for Greenaway and Huard on Tuesday were not returned.

Tepler said Greenaway was not satisfied with the conclusion of the criminal case against the girl, which is one reason for the civil lawsuit.

“When someone comes to me when they’ve lost a child … it’s really never about the money,” Tepler said. “They come to me broken hearted. What they want is justice.”