When are you arriving, March? The weather is fantastic that time of year.
Try and book an Airbnb within an estate, maybe that will help her anxiety a bit too.
We took a direct flight from SA to NY thats 14hrs. Its long, Im not going to lie. We flew with United, and it was a much more comfy flight than other airlines we have used. Also, they have their own terminal space at OR Thambo in Joburg if thst helps!
Having been to NY and staying in Brookyn, I will say there are a few similarities. One thats not the same is being able to walk in the streets at night. Its a big no no here. However, thimgs are more affordable here, and you can just use Uber X for safety.
We are currently in a heatwave. It pours down about every 4th evening, at least in Pretoria. But it is hotter than ever!
Maybe if you make some videos to show your mom what it looks like here, and how the airport looks will calm her down. People have an image in their head about 'Africa' and its a false perception.
I hope you can convince her. Let us know if you do, she will have a great time in our beautiful country.