Reeva Steenkamp's family says they believe in the justice system and that "the law must run its course", family spokesperson Tanya Koen told the media outside the Supreme Court of Appeal in Bloemfontein.
The State is appealing the jail sentence imposed on Oscar Pistorius, arguing that the six years' imprisonment on the murder charge is "shockingly", "startlingly" and "disturbingly inappropriate".
North Gauteng High Court Judge Thokozile Masipa had sentenced Pistorius to six years for the murder of Reeva on Valentine's Day in 2013.
