The estranged daughter of Oscar-winning actor Billy Bob Thornton was sentenced in Florida on Thursday to 20 years in prison for killing a child in her care.

Amanda Brumfield, 32, was convicted in Orlando in May of the aggravated manslaughter of Olivia Madison Garcia, the 1-year-old daughter of one of her close friends.

The child's mother, Heather Murphy, said after the sentencing that she was surprised at how long a prison term Brumfield received, but that it meant little to her.

None of it satisfies me. It doesn't matter...I won't ever see Olivia again, Murphy told reporters.

Brumfield contended at trial that Olivia fell out of her playpen and hit her head in October 2008, but prosecutors argued the child's skull fracture and brain bleeding were no accident.

The jury acquitted Brumfield of first-degree murder and aggravated child abuse charges.

Five-times married Thornton, whose former spouses include Angelina Jolie, has four children. Amanda Brumfield was the product of his first marriage in the 1970s.

Thornton's publicist, Arnold Robinson, told CNN after Brumfield's arrest that the actor was estranged from his daughter and has had no contact with her for quite some time.

Thornton won an Oscar for his screenplay for the 1996 independent film Sling Blade.