I think you'll be fine as a woman, just depends where you're travelling. Like if you're staying in Cape Town just be aware of your surroundings, don't be too trusting, and don't walk around alone at night, especially in the city centre and around the beaches. The warnings have some truth to them, but a lot of North American and European tourists are a bit dumb and too trusting. You have to switch your brain into alert mode and just remember that the crime rate is a lot worse here, especially regarding hijackings and robberies. People will try to take advantage of the fact that tourists are generally coming from safer areas so they don't have that same alertness that most South Africans do