Billy Bob girl on kid death rap.
Amanda Brumfield, 32, was babysitting her best friend's year-old daughter, Olivia Garcia, for an overnight stay when she died of a head injury.
Brumfield, who is estranged from her father, told a court in Orlando, Florida, that Olivia had hit her head when she fell out of a playpen but did not appear to be badly hurt.
She fell asleep on the sofa with the child but realised when she woke two hours later that Olivia had gone limp.
An autopsy revealed she had a fractured skull and bleeding and swelling in her brain.
But doctors testified it would have been impossible for Olivia's injuries to be caused by such a slight fall.
Brumfield, whose mother is Thornton's first wife Melissa Gatlin, was convicted of aggravated manslaughter.
She is to be sentenced for the offence in July.
At the time of the tragedy, Sling Blade star Thornton, 55, whose fifth wife was Angelina Jolie, said he had been estranged from Brumfield for some time.