Charlean Larue Welch was taken into custody by California Highway Patrol officers Monday.
While Maldonado's family is still grieving, they were happy to see some justice.
"Our condolences go out to the family. Our officers went to their home this morning, as soon as the arrest was made, to let them know. They were grateful," Office Brian Alvarez said.
The collision happened around 7:10 a.m. near Pacific Street and Glasgow Avenue on Sept. 28.
Maldonado was walking to school in a marked crosswalk when the driver of a tan Chevy SUV going about 40-50 mph failed to stop, striking the girl. The vehicle then fled the scene.
Maldonado was initially described as having life-threatening injuries. By the afternoon, officials confirmed she had died.
One eyewitness who saw the incident said she was outraged that the driver didn't stop. "You should have stopped and made sure you help her," Maria Ibarra said, through tears. "But you didn't. You just left her there."
Ibarra described seeing the moment of impact.
"The truck was coming, and she was crossing the street right here," Ibarra said. "Hit her, run her over, run over her... didn't even stop to see what was going on."
When she ran over to help the gravely injured Maldonado, Ibarra said the girl was still breathing.
"I was holding her hand and letting her know that she was going to be OK," Ibarra said. "Now she's not here no more."
After the fatal incident, the CHP released surveillance video showing the tan SUV traveling just a few miles above the posted speed limit in the moments before Maldonado was hit. Officers said they were unsure if Maldonado's death was due to the driver not paying attention.
Authorities said they were able to get Welch after reviewing the surveillance video and found the vehicle at a location where investigators believe she was trying to repair the SUV. They were then able to get Welch's address by running the license plate.
There was no immediate information on the charges that Welch might face. She may appear in court Wednesday morning.