Mr Cholmondeley-Warner wrote:The alternative is just to wait every time, and let the other party go first.
I'm wondering if the expectation is different because it's a mini-roundabout ... I mean the usual way to approach a larger roundabout is to give way to traffic already on the roundabout, but for a mini-roundabout it is perhaps to give way to traffic waiting to join the roundabout immediately to your right. She would have assumed you would be giving way to her, so in turn would be looking to her right checking if it was clear for her to move off.
Given that people have trouble looking in two directions at the same time, her priority would be to look right immediately before moving off as that would (normally) be the greatest source of danger.
The second point is that most people make little or no attempt to go around a mini-roundabout; it's sometimes awkward and you have to steer more than in necessary to make the turning, and moreover you have to steer relatively quickly, certainly more quickly than most people seem able to manage. Looking at the overhead view in Google Maps makes it reasonably apparent that the natural line from the 4 o'clock direction for someone intent on turning right is over the top of the painted island.
What could you have done differently? I think waiting longer to move off, to be certain that your way would be clear. The other point is that I wonder, from your description, where your attention was focused as you moved into the junction.