Look, to be fair, like I said above there hasn't been anybody reputable that I've seen who has claimed that they saw the original tweet in her timeline and screencapped it for that image. Maybe the news reports did? It's not clear, one story does say the tweet was deleted (or did it just appear to be that way when the reporter looked for a tweet that never existed anyway?).
Based on the rest of her posts, it's a bit inconclusive:
https://twitter.com/DlaminiZuma/with_replies
She doesn't seem to post a lot or frequently engage with other people's discussions, but she DOES use those characteristic .... quite a bit:
https://twitter.com/DlaminiZuma/status/850047350718570500
If the post DID come from her it's possible it was in a moment of anger, which is why it's so messy and poorly worded.