Derived from the wiki: Brusha is a proud, introverted, and emotionally complex Toon. She values skill and recognition highly, and her interactions reveal layers of frustration, hurt, and occasionally defensiveness. She is socially cautious. Although irritable or defensive, she has depth: her affection for art, her desire for recognition, and her subtle reactions to others' emotions demonstrate a sensitive Toon beneath the surface. After the show, Brusha changed significantly; she became very irritable. 

Her voice should be slightly raspy and teenager esque. Wendy (Gravity Falls) is a GREAT example.