Sadie is the secondary character in Girl vs. Monster. She is portrayed by Kerris Dorsey.
Sadie is Skylar’s best friend, who is as reserved and controlled as Skylar is confident and energetic. Traumatized in childhood, Sadie must now confront her own monster to overcome her fears and be the friend and teammate that Skylar, and the world, needs.
She had a fear of public speaking but manages to overcome it when she presented to a class about the brain's functions and nerves.
On Halloween, Sadie and her best friends Skylar and Henry plan to go to the ultimate Halloween bash and watch Skylar sing her heart out with rock band cutie, Ryan Dean. But, Skylar's plans are crushed when her parents make her stay home.
When she sneaks out the house, Skylar releases 15 years worth of monsters, and Sadie and Henry come along for the ride. Scared, Sadie flees with Skylar, the babysitter Cobb, and Henry, as they get approached by Deimata, a powerful monster who plans to finally stop Skylar and her parents.
Sadie, Henry, and Skylar soon find out that Skylar's parents are monster hunters and they are the 4th generation of monster hunters.
Now, realizing they must save Skylar's parents, Sadie and the gang must conquer all of their fears and fight the monsters.
Sadie and Skylar are best friends. They work together to fight off monsters. Sadie is always concerened about Skylar.
Henry and Sadie are also friends. They both share a friendship with Skylar. Henry gets bullied at school and is always picked on.
Theadosia is Sadie's monster.
- Sadie claims to get fear almost everyday.
- In her 5th grade spelling bee, she misspelled the word "goat" due to the witch tormenting her there.
- Near the end, she tells Theadosia she isn't afraid of of her by spelling out words.