The 27-year-old has been on trial at the High Court in Pretoria, South Africa for the last four months after he shot the model at his home on Valentine's Day last year.
Steenkamp's mother, who had never met the athlete during his relationship with her daughter, has been in attendance throughout the trial.
"I don't hate Oscar," Ms Steenkamp told Hello! magazine. "I've forgiven him. I have to, that's my religion, but I am determined to face him and reclaim my daughter.
"It's important for him to know I'm there, that Reeva's mother who gave birth to her and loved her, is there for her."
Pistorius denies murder by claiming that he mistook Steenkamp for an intruder when he fired four gunshots through the bathroom door.