On Friday just after 22:00, paramedics arrived to find that bystanders had pulled the 22-year-old woman and her child, as well as another family member from the wreckage, ER24 spokesperson Werner Vermaak said.
The mother and child were treated on scene before being rushed to Chris Hani Baragwanath Hospital.
"The driver, believed to be the uncle, sustained only moderate injuries and was treated for a shoulder fracture on the scene before being taken through to hospital.
"According to bystanders on the scene, it appeared as if the bakkie entered the intersection too fast and lost control, causing it to collide with the barriers and the embankment," Vermaak said.