Numerous cast changes occurred throughout the series, although none was as significant. Most notable was the replacement of Jane Wyman as Michaela's mother, Elizabeth Quinn. Wyman signed on to play the role for the third episode of "Dr. Quinn" in season one. Later Wyman turned down an invitation to return for another guest appearance in season two, as she had retired completely from acting by this stage (her previous appearance in season one marked her final acting role of any kind). Georgann Johnson was hired to replace Wyman in the role and continued throughout the remainder of the series, making one guest appearance each season and appearing in the final "Dr. Quinn" television movie.