Fernstar is a small, ashen gray she-cat with a darker gray stripe down her back and had ice-blue eyes.
When Willowpaw brings a half-conscious Ginger into camp, Fernstar is alarmed, and Ginger sees her before she passes out. After Willowpaw awakens her later, she watches Fernstar give Willowpaw her warrior name, Willowsplash. Fernstar privately meets Ginger after the ceremony, asking her if she will stay. Ginger says yes, and Fernstar is often seen sorting patrols. She and Gorseheart are very close. When Ginger is talking to her about Gray and his group, she reveals that Talon was her brother, once a fierce warrior named Talonclaw. Later, she gives Ginger her warrior name, Gingerheart, and console her when Ravenfeather continuously scorns her. She leads one of the patrols in the battle against Gray's group, and Gingerheart witnesses her killing Talon.