Harper, 74, who was diagnosed with terminal brain cancer earlier this year competed on the show, but was eliminated last month. She appeared on Tuesday's season finale.
"It was great to be with [my dance partner] Tristan [McManus] again and all my buds, all these lovely friends I made," Harper told People.com after the show, adding her health has been "pretty good" since she left the competition.
"I had a few little strange things but they probably would have happened anyway," the former "Rhoda" star said. "I don't have any big terrible symptoms, so as long as that's happening and I'm seeing my doctors, what's to complain about? There's people out there really suffering, so I'm feeling pretty good."