g_scheepers wrote: We're both from South Africa. When you say that we need to convince the ECO of her return to our home country after the 2 years, what do we need to provide them with?
As I said this is a subjective area and is based on the ECO deciding on the balance of probabilities that you will return home. There is no single document you can submit to prove this intention. The ECO will review your socio-economic factors such as ability to find a job in South Africa after your WHM visa. Since this is directly linked to the economic situation in SA as well as your skills/ qualifications it may be that in the ECO's opinion you are 'running' away.
What I have noted is that if you are from a 'good' income family, have a degree and are likely to be easily employed in your home country then you get a WHM visa. There are also political pressures in operation in the WHM - the governments of Australia, New Zealand and Canada actively promote the scheme via ongoing consultation with the UK government - its almost a form of labour interchange albeit supported by reciprocal schemes. It is best to proceed with the visa application as soon as possible because there is talk of a quota system being implemented.
Good luck