Tamarla Owens said that whenever she tries to discuss the shooting with her son, he withdraws from her.
Police say Owens' son shot and killed six-year-old Kayla Rolland last month at an elementary school near Flint, Michigan.
Owens says she prays for Kayla and her family every night and feels sorry about what happened.
Owens denied reports that she is a drug addict. She says her son was living with her brother because she had to work two jobs.
A 19-year-old man living at the house where the boy had been staying has been charged with involuntary manslaughter for allegedly leaving the gun used in the shooting where the child could get it.
Last week the Beecher School District expelled for 90 days the 6-year-old boy accused of the fatal shooting.
Superintendent Ira Rutherford has recommended that the boy be expelled for three months, in accordance with Michigan's school anti-weapons law.
Over a three-month period last year, 657 Michigan students were expelled from kindergarten through 12th grade for up to 180 days for bringing weapons to school, according to state Department of Education statistics.
The state law says students caught with a gun must be expelled, but they are allowed to return, similar to a suspension, after the penalty time.
The boy, his 5-year-old sister and 8-year-old brother currently are getting educational services at home. They are in the temporary custody of their maternal aunt.
Rolland was killed by a single gunshot that police said was fired by the boy while the two were in their classroom at Buell Elementary School in nearby Mount Morris Township.
The boy, who was reportedly angry from a playground scuffle with Rolland, is believed to be the youngest perpetrator of gun violence in a recent spate of school shootings.