Sonja Barker-Finch is a rarely seen character and is both Hyacinth's neighbour and nemesis. It seems that she is in a similar "Can't afford it but I'm still posh" position to Hyacinth.
Competition with Hyacinth:Edit
Hyacinth's rivalry with Sonja and her efforts to get ahead of her are running gags throughout the series and in some episodes are central to the plot.
In 'A Celebrity for the Barbecue' Hyacinth is outraged at the fact that Sonja had a wealthy owner of a supply of building materials attend her barbecue; which she was not invited to. In return Hyacinth seeks to do better by hosting her own barbecue and inviting C.P. Benedict, the owner of a large garden centre who had been on television and was acquainted distantly with Richard.
Relationship with other characters:Edit
Sonja seems to be on good terms with Elizabeth and Emmet. For instance it is implied that Elizabeth and Emmet had been invited and had attended her barbecue; Elizabeth looking pleased that Hyacinth wasn't invited.