"He's such a nice guy," the actress, 30, told TV's Inside Edition, the Associated Press reports. "He's made some mistakes, but everybody else doesn't have the whole world pointing their finger at their mistakes."
Jackson has long been a staunch supporter of the aspiring rapper, who is currently on the road promoting his CD, Playing With Fire. In May, while Britney Spears was expecting her second child with Federline, Jackson told PEOPLE: "He's an amazing dad. … He's a good guy, and when he's not with (his kids), it hurts his heart that he misses them so much."
Federline, 28, became involved with Spears while Jackson was pregnant. She gave birth to son Kaleb, now 2, in July 2004, two months before Federline and Spears wed. Jackson and Federline also have a 4-year-old daughter, Kori.
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Jackson, who starred in the 1996-2001 TV series Moesha, says Federline does not pay her child support, but "he does pay for their school, and they go to a very expensive private school."
She also thinks that celebrity breakups and divorces are nothing to celebrate. "I don't understand why people take so much joy in other people's pain."