Marli van Breda has undergone extensive surgery and is in a critical but stable condition at the Vergelegen Mediclinic.
Van Breda's mother, Teresa, her father, Martin and brother, Rudi were brutally killed with an axe at their Stellenbosch Golf estate home this week.
According to News24.com, van Breda was recovering in hospital as she underwent surgery for serious injuries including head trauma and a severed jugular.
Meg Fargher, Principal of Somerset college told the website that Van Breda's boyfriend was not at school since the tragic incident occurred.
Marli van Breda started at the college last year.
“She’s a lovely, popular, clever girl,” said Fargher.
Fargher said the Van Bredas had been hands on and were supportive of the pupils at the school.