It's probably not Adrienne Hill's fault. Katerina had a whole deck's worth of cards stacked against her. First and foremost, new incoming producer John Wiles was only the producer of the show for about the length of a longish afternoon, and during that time he changed his mind approximately four hundred thousand times about what he wanted to do with the companion. What he wanted to do first with the companion was fire her. That would be orphan girl of the future Vicki, who Wiles had written out immediately upon taking over for reasons best known to himself. With apparently two and a half minutes careful preparation, she was replaced with a handmaiden from ancient Troy, marking the first time that a companion had come from the distant past. Then he decided that wouldn't work, killed her off, changed his mind twice more, and eventually ended up shoehorning Jackie Lane as Dodo into a story nominally about French History. So, there's poor Trojan handmaiden Katerina. She only appears in 5 episodes, and of those only one actually still exists. She spends most of that saying variations of "I have absolutely no idea what the hell is going on!" in a stilted faux-historical accent. Then they chuck her out an airlock. It's hardly a set of circumstances that lends itself to becoming a fan favourite.