She belongs to the category of children who see Death as a skeleton, something most adults avoid doing. However, she also actually sees the monsters with which her first governess used to scare her. Since she cannot persuade Twyla that monsters do not exist, because they patently do, Susan uses the poker to dispatch them. By doing this, Twyla is a firm believer in the power of the poker to get rid of unwanted guests. Twyla is not squeamish about the idea of monsters being beaten to death, indeed is prepared to wait around to see it happen. Unlike her brother Gawain, she does draw the line on deliberately stepping on the cracks between the paving stones to get the "tear you to bits bears" into trouble. She is correct in believing that the nursery poker only kills monsters.
When Twyla told Susan that other children in the park said that the Hogfather did not exist, Susan asked her, “Does it matter if you get the presents anyway?” Twyla’s answer, from beneath the blankets, was ‘es. In this respect she is similar to Banjo Lilywhite, another "five year old", and in the big scheme of things they seem to be right as the events of the novel prove. Twyla concedes that she is consistently urged by Susan not to lithp in order to sound ingratiatingly cute.
In the movie, Hogfather, Madeleine Rakic-Platt played the part of Twyla.