Twirl was a young squirrel who doesn't have any parents. She was orphaned and raised by her Aunt Cherry. Twirl was in Sepia's choir, and did not trust Mossberry though her aunt was devoted to him, saying: "But Juniper's a good priest isn't he aunty?" Then, her aunt used to hit her, because she went angry.
Later her aunt tried to take her to a meeting with other Mossberry followers, but Twirl attempted to get away calling attention to herself and her aunt. Urchin and Sepia noticed her, and cornered her aunt and two other hedgehogs to ask them what was going on. Twirl said that she wanted to be with Sepia and not go to Mossberry.
At the time of the first Rage Tide, Twirl snuck over to Sepia as Mossberry and the king were arguing. A rage tide swept her out to water, and Sepia caught her and tried to climb up with her. Urchin goes out and tries to save both of them, but Sepia only hands over a screaming Twirl. She was rescued, but Sepia was not.
Twirl was very close to Sepia, and always asked the adults where Sepia was and when she would be back. In another rage tide, she was pinned by a falling limb, and was dug out by Cedar and Urchin, but the ground beneath her caved in, and she fell on the missing Furtle and Spirtle, technically finding them.
When Twirl found out that Sepia was being brought home, she gathered some Swan feathers and refused Fingal's help. She was determined to carry them herself. She took them to Urchin, asking if Sepia was back yet. When he said no she gave him the feathers, which were made into a pillow for Sepia.
When Sepia woke up in the infirmary, Twirl was one of her first visitors, giving her a shell bracelet she had made for her.