Ms Anderson, who is seeking a divorce, said she was "very proud" of her husband for having had the courage to plead guilty following his arrest in February after she complained he had struck her as she held the couple's seven-week-old boy in her arms.
Mr Lee, a drummer with the rock band Motley Crue, did not contest prosecution charges that he kicked his wife twice in the back and once on the buttocks.
Ms Anderson filed for divorce shortly after the incident and has said there is no chance of a reconciliation.
But standing outside the Malibu courthouse in California on Tuesday, the 30-year-old actress told reporters: "I'm very proud of Tommy. I'm happy that he took responsibility for this, and I think it's the first step toward healing. And I'm anxious for him to see his kids and I'm sure his kids are anxious to see him."
Mr Lee, who remains free on $500,000 (pounds 300,000) bail pending his sentencing on 20 May, will be allowed to see his children once a week.
Ms Anderson first filed for divorce two years ago, but the couple reconciled when she said she wanted to help Mr Lee overcome his alcohol problems. Mr Lee still faces criminal charges in Arizona for allegedly assaulting a security guard during a Motley Crue concert last year. He also faces a civil suit filed by a photographer who claims the drummer assaulted him at the Viper Room night club in Los Angeles in September 1996.
Last year a videotape of Mr Lee and Ms Anderson having sex, which they themselves made, became a best-seller in the American adult home video market.Reuse content