This is always a tricky situation that must be dealt with by any employer with great care and circumspection as there may be potential problems if the correct procedures are not followed by the employer, whether it is a big company or an individual who wishes to terminate the service of a domestic worker.
The crisp response to your question is that, in the first instance, you will need to prove that there is a valid and fair reason for terminating the services of the worker and also that a fair procedure has been followed. If you do not follow the steps, the employee could approach the CCMA for assistance and this could have substantial financial implications for you.
Secondly, there must be a written termination in terms of the employment contract (which I am certain that you concluded with your domestic worker).
This is a VERY broad and brief sweep through your question – these are the basic principles that must be followed, but I will be happy to provide you with further information or assistance – please do submit a further question to the website with more comprehensive details.