He pushed her out of the way, saving her life, but in the process took much of the brunt of the impact himself.
Brandon was rushed to Harlem Hospital. His suffered serious injuries - a bruised head and body and a shattered femur. During a two hour surgery, doctors replaced it with a titanium rod.
Brandon is heavily sedated, but his sister and mother say he is aware of what he did.
"It was the first time he smiled -- he was happy that he pushed her out of the way and that was the one thing that cheered him up in an otherwise painful and confusing and terrifying experience," Ericka Phillips, his sister, said.
His mother and sister told Eyewitness News that they hope the driver who sped off takes responsibility and comes forward.
"It makes me angry that someone was driving so fast and that they didn't stop and the idea of this happening to any child is unacceptable," Ericka said.
As Brandon recovers, they continue to stand in awe of his heroism.
"I'm so proud of him. I don't know many people who would do it. Your first instinct is self-preservation," Sedonia Phillips, his mother, said.
Branndin is here visiting from Chicago. He was taking part in a selective arts program for poetry and song writing. He had been eager to leave Chicago for the summer because he'd been mugged at gunpoint by teenagers this past spring.