You mean scouted to be a model? It's definitely possible, but the fashion scene is probably smaller in South Africa than it is in other countries, so it might be harder.
However, the stories of models being scouted are always the same: Some amazing talent scout drops out of nowhere and pulls a girl off the streets and turns her into a superstar.
In fact, when I researched the history of the only South African model I'd ever heard of: Candice Swanepoel, it seems that story fits her down to a tee.
She was spotted at the age of 15 in a Durban flea market. Now, she is a megastar best known for her work with Victoria's Secret underwear.
So I'd say don't give up on your dream, but also realize it's going to be hard getting that break.