She will be in the spotlight on Sept. 11, however, when she begins to deliver the lengthy verdict on Pistorius, accused of murder in the shooting death on Valentine's Day 2013 of his model girlfriend Reeva Steenkamp.
If convicted of the most serious charge of premeditated murder, Masipa could sentence Pistorius to at least 25 years in prison. She could also find him guilty, but impose a lesser sentence because of personal circumstances. Or find him not guilty. It is a remarkable range of judicial authority.
The judge has a reputation for coming down hard on men convicted on charges of violence against women. She once sentenced a house robber who raped three women during his reign of terror to 252 years in prison, and handed a life sentence to a police officer who killed his wife during an argument about their divorce settlement.
South Africa does not have a jury system and Masipa is assisted by two assessors, who both have legal training and work within the legal system. While they can, if both disagree with the judge, overturn her ruling when it comes to the determination of guilt or innocence, she alone determines the punishment in the case of a conviction.
The Pistorius family has in the past said they are willing to rely on Masipa's judgment.
“As a family, we are confident by the thoroughness and detail of this judgment and Judge Masipa’s commitment using every avenue to ensure a fair trial,” Pistorius' uncle Arnold Pistorius said after Masipa ruled that the double amputee be sent for psychiatric evaluation.
It is a confidence that Masipa strives to have infused in her court.
"She's very clever, very professional. She comes from a human rights background, so that's the point – you must allow people to feel like they've had their day in court, to feel as if they've been heard," Susan Abro, a senior attorney who served with Masipa on the electoral court for six years, told ABC News.
Masipa, 66, was born in Soweto in 1947, one year before the National Party, with its official policy of apartheid, was voted into power. She was the oldest of 10 children and her first name translates to "happy."
As a former newspaper reporter, she was once arrested for protesting against the arrest of her male colleagues. Her white jailers ordered her and her fellow detainees to clean their cell’s filthy toilet, but she stoically refused.
The legal teams for Pistorius and the prosecution, as well as all the witnesses and anyone else in court, addresses Masipa with the honorific "My Lady." The lawyers for both sides, which consist mainly of white Afrikaner men, treat the judge with obvious deference, a remarkable development for a legal system that just 20 years ago was based on the racist apartheid system.
The judge is aware of her position. She was once quoted saying, "It is a tough place to be, because for a long time it was only men who sat here, and in our culture it's even tougher, because some men are just not used to seeing women giving orders. But one gets used to it. It's not you as a woman who's there – it's the position that you fill. So you just get on with it."
Lawyers who appear in her court know they must be ready.
"She doesn't suffer fools at all. One doesn't come to her court unprepared," said a Johannesburg-based prosecutor who was once castigated by Masipa for forgetting a file at the office.
That prosecutor, who asked not to be identified, said Masipa generally arrives at court by 6:30 a.m., two hours ahead of her colleagues. "She works incredibly hard and is extremely meticulous, always paying attention to detail, making sure every 'i' is dotted and 't' crossed."
A trailblazer for most of her life, Masipa was only the second black woman appointed as a High Court judge in South Africa. After a brief career as a social worker, she became a reporter at The Post, where she eventually edited a weekly women’s section, a post previously reserved for a white woman. She began studying law at the height of apartheid and became a lawyer in her 40s.
With the cameras in court firmly fixed upon her since the trial started in March, Masipa has given no indication of whether or not she believes Pistorius' version of the shooting, taking notes and listening with clasped hands as witnesses testified in her court. Her control of courtroom has been absolute and unquestioned and she has chastised the prosecutor and Pistorius' lawyer. Masipa has also shown a compassionate side, gently asking Pistorius if he needed more time to recover after a particularly emotional outburst from the athlete.
An intensely private person, Masipa has given very few interviews over the years, and since being appointed to oversee the high profile trial she has turned down all requests for interviews.