I went to school and college in South Africa. I have seen how it has changed since we first arrived there from Zambia in 1976. We emigrated to Zambia, from Scotland in 1970. My brother, sister in law and two nephews still live outside Pretoria on the Hartbeespoort Dam. I am planning a trip to S.A. in September. What I can tell you is it won't be to spend anytime in Johannesburg. Sad really because I did spend 4 great years there when I attended college in the '80's.
I have taken my wife to S.A. twice in the last 10 years. I opted to take her up to Madikwe Game Reserve, near the Botswana border for her first Safari experience. The second visit was primarily to visit Capetown and the Stellenbosch wine region. I spent time with my family on both occasions but that was on the shores of a lake, in a gated community, with security guards manning the gate. There is enough written about traveling in an around the Johannesburg area.
Well noted that
@Ruffian flew straight in and then straight out of Oliver Tambo (Jo'burg) to Skukuza. The Kruger National Park is a great location and I agree Sabi Sabi is a great place to go on Safari. I also agree with
@30t1 and others comments on Capetown and the Airbnb owners comments on the Western Cape versus Johannesburg.
In a previous life I worked for Abercombie & Kent and was based in Nairobi. During that time I was fortunate to travel through many of the Kenyan, Tanzanian and South African parks with prospective clients on familiarization trips. When we did the S.A trips we gathered the clients in Pretoria and only used the Johannesburg airport to fly out to parks and then down to Capetown. It was a company decision not to include Johannesburg on the clients itinerary.
I can understand how your wife can't shake the safety aspect.
Why not book a Game Lodge in the Kruger area, or one of the smaller reserves, then go on to enjoy Capetown for a few days? Perhaps with enough advanced notice your wife can encourage her friend and family to join you all on part of the trip?
When I go in September, the plan is for all of us to drive straight out from the airport into the country. We have booked an Airbnb in the Eastern Highlands for a week of R & R and a spot of trout fishing.