KANSAS CITY, Mo. -- The mother of a young girl known for years as "Precious Doe" pleaded guilty Thursday to second-degree murder in the death of her 3-year-old daughter.

Michelle Johnson, 31, of Muskogee, Okla., also pleaded guilty to child endangerment, abandoning a corpse and tampering with evidence for not helping her daughter as she lay dying after allegedly being abused by her stepfather.

As part of the plea agreement, Johnson will testify against her husband, Harrell Johnson, who is charged with first-degree murder, assistant prosecutor Tim Dollar said. Prosecutors plan to seek the death penalty for Harrell Johnson.

In exchange for Michelle Johnson's plea, prosecutors will recommend she serve a total of 25 years, Dollar said. If she had gone to trial and been convicted of second-murder, Johnson could have been sentenced to life in prison.

Johnson's trial had been scheduled to start Jan. 22.

Prosecutors said Johnson did not seek help for the girl, Erica Michelle Marie Green, who was dying after being kicked by her stepfather in a Kansas City home.

Prosecutors allege Harrell Johnson, also of Muskogee, Okla., was high on drugs when he kicked Erica because she wouldn't go to bed. They allege he left her to die, then later decapitated her body.

Erica's body was discovered in a Kansas City park in 2001, and her head was found several days later. The child was dubbed "Precious Doe" and activists kept attention on her case until the Johnsons were arrested and she was identified in May 2005.

The Johnsons were arrested in Muskogee, Okla., after Kansas City police got a tip from a family member linking them to Erica's death.

Michelle Johnson, also known as Michelle Pierce, was serving prison time in Oklahoma for larceny when Erica was born in 1997, reports show. The child almost immediately went into the care of foster mother Betty Brown and remained there until Michelle Johnson took her to Kansas City while looking for work.

A funeral was held for the child in December 2001, drawing hundreds of people who didn't even know the little girl's name. The girl's body was exhumed in July 2003 so experts could make a lifelike bust of what she may have looked like. She was buried a second time in Kansas City.

Reacting to Michelle Johnson's emotional plea Thursday, community activist Alonzo Washington, said, "Knowing that Michelle Johnson was at the prayer vigils, knowing that she still married a man after he murdered this child is just a deep thing."