Gallagher has also provided the voices of some of the letters in CBeebies' Alphablocks, and in the popular Cbeebies animated series The Octonauts as Dashi Dog the photographer, and the voices of Nicole Watterson, Penny Fitzgerald, Teri, and Margaret Robinson in the Cartoon Network show The Amazing World of Gumball, in which she does an American accent. Gallagher does the voice of Mater's Computer in Cars 2. She also voiced KT in the 2008 version of Pinky and Perky, Egbert & Gilda the Pigeon in Poppy Cat, Hugo in What's the Big Idea (CBeebies), and several characters such as Emily (UK), Rosie (UK), Belle (UK/US), Daisy (UK/US), Mavis (UK/US), Annie & Clarabel (UK/US), Judy (UK/US), Lady Hatt (UK/US) and other characters alike on Thomas & Friends.
In 2010, she voiced Queen Titania, Mrs. Walker, and Fern in the UK version of the movie Rainbow Magic: Return to Rainspell Island. She does the voice of Matilda, Young Stella and Zara the Cruzeao in Angry Birds Space.