The sentencing in Orlando was reported on the Central Florida News 13 Web site.
Brumfield, 32, was convicted in May of manslaughter in connection with the 2008 death of her friend's 1-year-old daughter. The child died of a head injury after Brumfield babysat her.
Although Brumfield insisted the girl fell and hit her head as she tried to climb out of a playpen, prosecutors argued her injuries were not consistent with a fall from that height.
Thornton's publicist, Arnold Robinson, said shortly after the incident the actor "has had no contact with (his daughter) for quite some time."
"When informed about this situation, (Thornton) commented that, 'Anytime a baby's life is lost is an unimaginable tragedy and my heart goes out to the baby's family and loved ones,'" Robinson told CNN in a written statement.
Thornton, 56, has been married and divorced five times and is the father of four children. He is best known for his Oscar-winning film "Sling Blade," which he starred in, wrote and directed.