The 58-year-old singer is set to appear on 'CBS Sunday Morning' on Sept. 25.
"I got the call, and I went over, and I saw her and that was that," Wynonna says on CBS Sunday Morning, in a preview clip of a segment that will air in full on Sept. 25. "I said goodbye to her in the hospital, and I closed her eyes, and I kissed her forehead and that was that. And the next thing I know, I'm sitting here on the front porch, on the side porch ... you know, and I'm just tryin' to figure out what's next."
Naomi died from a self-inflicted gunshot wound on April 30 at 76 years old. The family said at the time that Naomi had suffered from PTSD and bipolar disorder.
Wynonna's sister, actress Ashley Judd, previously revealed that she was the one to discover their mother's failing body in the wake of the gunshot and dialed 911. She and the family have since asked a judge to seal police reports and recordings made during the course of its investigation into her death. They said that, should the police reports and recordings be made available to the public, it would bring "significant trauma and irreparable harm" to the family.
"I did not know that she was at the place she was at when she ended it because she had had episodes before and she got better," Wynonna now says. "That's the challenge with mental illness. It's really, really mysterious. And that’s what I live in, is like, 'Was there anything I should have looked for or should I have known?' I didn’t. That's why it's such a shock."
Agreeing with journalist Lee Cowan that mental illness is a "cruel disease," Wynonna continues, "People think it's a character flaw and they don't know that it's this incredibly dark and light experience. She had incredibly great days in the middle of the dark days. That's why it's so confusing."
In the weeks following Naomi's death, Wynonna tearfully announced that her previously scheduled The Judds tour would continue on as planned. "That's what Mama would want," she declared at the time.
"I feel her nudging me. And sometimes, I laugh," she now says. "And sometimes, I say, 'I really miss you. Why aren’t you here so we can argue?'"
Wynonna's interview will air on the Sept. 25 episode of CBS Sunday Morning at 9 a.m. ET on the CBS Television Network and streaming on Paramount+.