Soda is a child with Chug's appearance and Maple's hair color. Her eyes are almost unnaturally wide with a slight shine in the pupils.
Soda was a cute little girl and she always wants to go for a ride on Sal's shoulders.
She was also likely unfamiliar with the dangers of the world as she showed no negative reaction to Sal being covered in blood and wielding a knife.
Soda lived a simple and carefree life in Room 303 of Addison Apartments with her parents and shared a strong bond with Sal and Larry.
When the Devourers of God sprung into action and the Dark Capsule was planted in Addison Apartments, all residents were infected. On the spectral plane in said event, Soda somehow came into possession of a Dark Glitter Pony from Charley's room.
The day of the Red-Eyed Demon infestation, Soda and her father were both infected by Red Eyes and were sequentially slaughtered by Sal to prevent it from spreading.