The complete "Batman" TV series is finally being released on digitally remastered Blu-Ray Video on November 11, 2014. Get it here. Watch the trailer and you will see a clip of Donna with Cesar Romero. She plays The Joker's moll as "Susie" in the popular two-part episode "The Joker Goes to School" (3/2/66) and "He Meets His Match, the Grisly Ghoul" (3/3/66) on ABC.
Some trivia: On the 1966 Batman Message Board, Donna was #1 pick of 'Molls who changed sides and helped Batman". Donna felt that Cesar Romero transformed himself into The Joker character seamlessly. She learned to play her role in a more campy way from him. Most of the garments she wore on Batman were from her personal wardrobe with the exception of the cheerleader outfit.