Semeria Greene is charged with murder in the Dec. 30 slaying of her daughter, Tameria.
A petition filed Monday in Wayne County Juvenile Court on behalf of the state Department of Human Services says Tameria's 4-year-old brother witnessed her death.
The petition was filed in a neglect case involving Greene's four sons. It says the boy told child advocacy workers his mother "had a big knife and cut his sister and his mother killed Ti-Ti."
The state wants to end Greene's parental rights to her other children. A pretrial hearing is set for Jan. 24.
Greene is being held without bond.