The Ballad and the Source by Rosamond Lehmann

In her letters Jessica Mitford mentions a woman named Mrs Hammersley, a friend of Jessica's mother. She seems to be an eccentric woman, but Jessica writes of her affectionately. She is referred to as The Widow, or, in this quote, the Widding;

Shall I tell you all about the Widding?... I think you can imagine her from reading the Ballad and the Source, & from my descriptions. She arrived to meet me at the boat (it's about 2 hours train & 1/2 hour boat  from London) looking very characteristic, swathed in black scarves, yellow face, jet black hair, somber large eyes. Also, characteristically, she had co-opted a neighbour to drive her to meet me & made her drive us both home.

                                     letter to Robert Treuhaft 1955

I found this picture of Mrs Hammersley as a young woman. It was painted by Philip Wilson Steer in 1907. I don't know whether a character in The Ballad and the Source reminded Jessica Mitford of Mrs Hammersley, or whether Rosamond Lehmann actually based one of the characters on her. 

However, by the power of Amazon and their 1p books I now have my own copy. Reading the blurb on the back I see that it features Sibyl Jardine, 'an enigmatic and powerful old woman'. I wonder if Sibyl is Mrs Hammersley. The blurb also claims that 'Sibyl Jardine is Rosamond Lehmann's most formidable literary creation'.

I haven't read anything by Rosamond Lehmann before, and I'm looking forward to getting started on this one.