She is first seen in "Chapter 1: The Hidden People", where she is pregnant. When Hilda sought out the Mayor to try and negotiate a truce with the Elves, who wanted both her and Johanna evicted from their houses, the Mayor angrily dismissed her. Unknown to him, Angelina crawled into Hilda's hair. When Hilda noticed, she threatened to let Angelina stay there forever unless the Mayor agreed to tell her where the Prime Minister lived. The mayor reluctantly agreed, after which Hilda returned Angelina to him.
In Chapter 2: The Midnight Giant, it turned out Angelina had given birth while hiding in Hilda's hair, resulting in her young crawling around Hilda's hair. Johanna discovered them and gathered them in a box.
In the graphic novels, she only appears in the story "Hilda and the Midnight Giant". Her role here is identical to the animated series.