Mya Peterson is the daughter of Theodore Peterson and Diane Peterson, and the younger sister of Aaron Peterson. She is the only playable character in Hello Neighbor: Hide and Seek. Mya dies when Aaron pushes her off the roof at the end of the game. Her best friends in Raven Brooks were Maritza Esposito and Lucy Yi.
Mya is a 10 year old girl. Her eyes are blue and her red hair is gathered in pigtails. Her eyebrows are small, unlike her brother. Additionally, she has a small nose and freckles. Dressed in a striped blue and white short-sleeved shirt and turquoise dress with small suspenders on top. There is a bracelet on her right hand. On her feet, she wears sandals with orange bows. She has a crow tattoo on her left wrist. This appearance is also used in Stage 5.
Mya's clothes have changed a bit. Mya is now wearing an ocher short-sleeved shirt. She has a special explorer hat. She is wearing pale beige shorts. Now, instead of a bracelet, she has a wristwatch. Instead of sandals, she has brown boots.
She looks like an ordinary thief. She is wearing black gloves and a mask. She also wears a black and white shirt with long sleeves. She is wearing dark gray pants and a hat. He also wears dark gray boots.
Dressed as a firefighter. She is dressed in special firefighter clothes in red with yellow accents. She has a special fire helmet. She also has a black belt with a gold buckle. Now she has brown shoes.
Mya looks almost the same as usual, but the clothes look more disheveled and pale. She has pale green tattered skin. Hair and eyebrows have a paler shade. On her right foot, the sandal has become more disheveled, and on the left foot is completely absent.
This is a piece of cardboard on which the outline of a child-girl is drawn. On the cardboard, you can see pigtails, white eyes,and a nose. On the painted child, you can see a dress with small suspenders.
Hello Neighbor: Hide & Seek: Playing hide and seek with her brother while their mom, Diane, is preparing breakfast. Then both parents leave, and the children continue their game. However, only Theodore comes home; he falls to the floor in tears and her mother’s bag in her hands. While playing hide and seek, her brother Aaron accidentally pushes her off the roof. Mya did not survive the fall.
Act 1: Her shoes are in Mr. Peterson's House at the entrance. You can also see a dream in which Theodore buried her with the shovel.
Act 2: Her coffin is buried in the backyard of Mr. Peterson's House. In the coffin is only the key to the dollhouse, which represents Mya. Also, her shoes are in Mr. Peterson's House in the entrance. You can also find a roller coaster dream where it is on the roof.
Act 3: She can be seen in a photograph of the Peterson family in the family room, as well as her shoes.
Story excerpts featuring Mya are shown in the dreams of Nicky Roth.
Mya is a kind girl, as shown when she tried to cheer Aaron up after their mother died. She has a wide imagination and likes playing. Mya has a doll which she really loves to play with.
Mya is shown to live with her father, Theodore, her mother, Diane, and her older brother, Aaron.
Hello Neighbor - December 8, 2017
Hello Neighbor: Missing Pieces - August 28, 2018
Hello Neighbor: Hide and Seek - December 6, 2018
Hello Neighbor: Waking Nightmare - December 26, 2018
Hello Neighbor: Buried Secrets - July 30, 2019
Hello Neighbor: Bad Blood - December 26, 2019
Hello Neighbor: Grave Mistakes - August 4, 2020
Hello Neighbor: Puzzle Master - December 29, 2020
- Mya is voiced by Varvara Pronina 
- Mya is referred to as Sister in the credits of Hello Neighbor: Hide and Seek.
- Initially, Mya was not a confirmed character, but in the full game, the developers confirmed her presence in the game.
- Mya herself has never met in the Hello Neighbor, only in Hello Neighbor: Hide and Seek. She can be seen only in the form of a model drawn on cardboard, or in a family portrait.
- In Hello Neighbor, you can find some things that belong to Mya (dollhouse, shoes, and others).
- For the first time, Mya appeared in Secret Neighbor’s first trailer, “Hello Neighbor Battlegrounds Announce Teaser,” running to Nicky's company.
- Diane Peterson refers to Mya as "Mouse".