This is Henrietta Reading, by Henry Taylor Lamb (1883 – 1960), an Australian-born British painter. A follower of Augustus John, Lamb was a founder member of the Camden Town Group in 1911 and of the London Group in 1913. Henrietta was his daughter by his second wife, the rather wonderfully named Lady Pansy Packenham. She grew up to be a landscape gardener under her married name, Henrietta Phipps.