In the interview, Smith tells how her son Daniel was excited when he heard the news of his sister, DannieLynn Hope, being born and how he wanted to come see her right away, Entertainment Tonight reported.
Daniel Smith died in the hospital bed next to his mother, reportedly of a mixture of Lexapro, Methadone and Zoloft.
Howard K. Stern, Smith's attorney and lover, who was also interviewed, spoke of what he remembers of Sept. 10, the day Daniel died.
"Well, I remember Anna saying 'Howard, Howard, wake up! Daniel's not breathing!'" said Stern. "I went over and checked his neck and I didn't feel anything and we immediately called the nurse."
"He said, 'Sit down'... he said, 'Daniel's dead.' I said, 'What are you talking about? and he said, 'Daniel's dead,'" said Smith, remembering when Stern told her the news.
"I thought they were playing that game they play on TV ... 'Punk'd,'" said Smith, referring to Ashton Kutcher's MTV show.
Notable deaths of 2014 [PHOTOS]