How did they know NGEMPELA?

A woman from eThekwini, Kwazulu-Natal, is sitting in the bar with two guys beside her.

The first guy say to the barman,  "Johnnie Walker. Single."

And the second blurts,

"Jack Daniels. single."

At that, the bartender approaches the lady and asks, "And you ma'am?"

"Ntombizodwa Kubheka, married."