Hayridge also played Hilly, the male Holly's female opposite from a parallel universe in the Series II finale "Parallel Universe". The story explanation for Holly's change between the episodes was that Holly had fallen so madly in love with Hilly that he transformed his face to resemble hers as an act of affection. She also got a unique chance to be seen from the neck down when she played one of Ace Rimmer's lovers (a parallel universe, human version of Holly) in "Dimension Jump"; in the commentary Hayridge expressed disappointment that her uttering of Ace's catchphrase "What a guy!" was the only one that was cut from the episode.
Hayridge left the series due to the decision to drop the Holly character as superfluous during the "Starbug is lost" story arc of Series VI and VII, although around the time VI as produced, she reprised the role of Holly for the Danny John-Jules music video of "Tongue Tied", alongside her predecessor (and successor) Lovett. She also played the role when the two Hollys then appeared together in linking material for the game Beat the Geek.