Earlier in the week, Simpson had confirmed reports that Ashlee was in negotiations for a return to NBC's "SNL," where she was caught using background vocals last October.
The 20-year-old singer's mishap was attributed to acid reflux disease.
"We are going to push 'SNL' back because we are doing 'The Oprah Winfrey Show' for one hour," Simpson told "Access Hollywood" on Wednesday. "['Oprah'] is going to be the first interview and the first place where Ashlee sings."
Ashlee's new album, "I Am Me," is set for release Oct. 18.
"We are working on the date" to appear on "Oprah," her manager-father said, "but it's going to be right before the release of the record. It's in the second or first week of October."