How lovely for your friend. How far away was she from Carole and George? (Just out of interest.) It's nice that they can live "normal" lives in Pangbourne and that they're not instantly recognised by everyone, which I was surprised about because I can imagine that everyone in the UK knows or at least has some idea of who George is. If I saw them in a casual situation like that I'd probably recognise George straight away but it might take me a bit longer to guess who Carole was. I don't think I would go up to them though since they were in a private situation.
It was my sister's friend I don't know her myself. She works in a small shop in Pangbourne and she spotted them out the window across the road. As far as people recognising George goes, as he had on a hat and was wrapped up in his buggy it would be easy for people in the street not to recognise him but the family are a common sight around where they live so I don't think most people would bother them anyway.