Siobhan Cresswell (b. 1993) was a halfblooded witch and the daughter of Algus Cresswell and Diaphaneity Gypsum. Siobhan attended Hogwarts School of Witchcraft and Wizardry in 2004 and was sorted into Slytherin. She was a member of the Emotional Support Group that started in 2005.
- Dark Paradise
- Year 2: Chapter 6 - Scorched Ground (First appearance)
- Year 2: Chapter 7 - MFLCBS
- Christmas Break: Chapter 1 - The Other Malfoy