Cher, 67, told ABC News she was asked to guest judge Monday night, which will also serve as a tribute to her legendary music career.
"I know that people take this seriously," she said, adding she was surprised when producers asked her to guest judge. "I just don't want to be responsible for someone getting a different mark than a professional would give them."
"He's coming tonight to give me tips!" Cher said. "He said, 'Mom, you don't understand how seriously people take this. I'm coming over tonight and ... I'm going to tutor you.' Obviously, I'm going to need all the help I can get."
"Someone's going to have to do some cramming with me," she added.
"I don't know, I don't know how you judge it," Cher said. "I was there when Chaz was doing it and saw how difficult it was. I just don't want to miss some fabulous thing that someone is doing ... and that would be a big deal, and I wouldn't even know it!"