Naomi Judd died of self-inflicted firearm wound, Ashley Judd reveals

The younger Judd appeared in an interview with Diane Sawyer, which aired on Thursday on "Good Morning America.

She said her family had agreed that she share the cause of death of her mother.

"She used a weapon," Ashley Judd said. "A firearm. So that's the piece of information we are very uncomfortable sharing."

She and her sister Wynonna Judd announced on April 30 that they had lost their mother "to the disease of mental illness."

Judd said the family reluctantly shared the cause of death before it became public in some other way.

"I have both grief and trauma from discovering her," said Judd

who began the interview by thanking everyone for the support she and her family have received in the wake of their grief.

Ashley Judd said her mother "couldn't hang on" to be recognized by her peers.

The Judd sisters attended the ceremony and honored their mother.