Lucimarian Tolliver Roberts, 88, died Thursday evening, the network announced.
Roberts had planned to leave the show Friday for treatment for a rare blood disorder. She left a day early to visit her mother, who had appeared on "Good Morning America" several times as a guest, ABC affiliate WXYZ-TV, Detroit, reported.
Roberts is scheduled to start treatments next week for a bone marrow transplant from her sister, Sally-Ann, CNN reported.
"There's a point that really resonates with me when I think about this time of my life. Life provides losses and heartbreak for all of us, but the greatest tragedy is to have the experience and miss the meaning," Roberts said Thursday. "I am determined not to miss that meaning, because through it I have discovered that I have been given many gifts, gifts that will carry me through this difficult time."