Naomi Judd, the country music icon who died on April 30 at the age of 75, died of a self-inflicted firearm wound, her daughter, Ashley Judd, disclosed on Thursday morning.Ashley Judd made an appearance on “Good Morning America” to speak with Diane Sawyer about her mother’s death and how the Judd family has been coping in the weeks since. She said her family wanted to control the flow of information about the death before an autopsy was released.“She used a weapon…my mother used a firearm,” Ashley told Sawyer.