1921 or earlier
Along with the other eight oldest sisters, Romilda used to try to give Miranda the wrong incantation for every spell she attempted to cast, thus hindering her learning of magic. Miranda found learning spells complex enough as it was, given that the instructions that she found in the old-fashioned textbooks she was given during her school years were needlessly complicated.
As a result of the difficulty she experienced learning spells as a child, when she grew up, Miranda became quite an accomplished spellbook author, wishing to make teaching and learning about spells an easier task. When she released Book of Spells, Miranda had a few "special editions" (actually editions containing deliberate misprints) sent to her sisters, and as a result, Romilda was left with a tail that eventually vanished.
- Wonderbook: Book of Spells (First appearance)