The shooting happened just after 11 p.m. Monday night at Scott Street and the South Loop.
"I'm still overwhelmed," said their mother, Aurelia Hunter.
She said her son, Steven, was driving, his best friend was in the front passenger seat and his sister, D'Asia, was in the back passenger seat.
Steven was able to drive back to their house after the shooting.
"He was shot three times, but his sister was in the backseat and he had to get home," Aurelia Hunter said.
Aurelia's fiancee drove them to Fire Station 46 for help.
Police said Steven was shot three times. D'Asia was shot once. The friend was not hurt.
Investigators said the suspects pulled up next to them, started shooting and took off.
"This could not have been a mistake," explained Aurelia Hunter.
Police gave a possible description of the suspect's car as a silver or gray Chrysler 200.
The legal driving age in Texas is 16.