When the car came around to shoot at the home for a second time, residents called the police.
Detectives believe Alonza was not the mystery gunmen's intended target.
Her mother, LaVette Bryant, said nobody living in the house has a connection to gangs.
"We are honest, upright citizens. We don't do anything - harm - to anyone in this neighbourhood," she told NWCN.com.
A spokesman for Seattle Police said officers collected shell cases and other evidence at the scene but did not find the vehicle after a search.
Detectives from the specialist gang unit are investigating.
- UK Independent