When Obi-wan bring Luke to his family, he only find Beru, because Owen succombed to illness a few months ago. The farm is too much for one personn, so he stay, helping with the farm and raising Luke.
At the beginning, their wedding is a lie, only a way to help concel Obi-wan, but when Luke is eight years old, they realise it became more.

And Obi-wan is the one buying the droids, so they have extra time to escape the Empire, and Beru come with them.