[The picture is of William and May and the staff of the Kelmscott Press about 1893]
I was actually looking for more info on May's husband Halliday but found this fascinating information on Jane and May some of which was definitely new to me.
Mary Morris, 1862-1938
Date of Birth: 1862.03.25
Place of Birth: The Red House, Bexleyheath
Date of Death: 1938.01.16
Place of Death: Hammersmith, London
Mary, or 'May' as she was more commonly known, was the second daughter of William and Jane Morris. She was named Mary being born on Lady Day, the Feast of the Annunciation. His wife having given birth to a still born daughter in May 1861, D. G. Rossetti made a serious attempt to adopt May later in life. In 1890 May married Henry Halliday Sparling. It is thought that she had a still born daughter.
In her youth May Morris received her academic education at the all girl's day school, Notting Hill High School. At the age of eighteen she enrolled at the National Art Training School at South Kensington, taking embroidery as her special subject. She made an embroidered cover for Ellis' printed vellum edition of her father's Love Is Enough.
May shared the socialist concerns of her father. They were both members of the Hammersmith branch of the Democratic Federation which formed at Kelmscott House on 14 June 1884. She worked consistently by his side in the Socialist cause. At the age of 23 she was her father's chief assistant in his decorative arts company. She eventually took over the management of the embroidery section of Morris and Co. Like her mother, May modelled at times for D. G. Rossetti.
In 1885 May fell in love with Bernard Shaw. Together they formed a 'Mystic Betrothal'. In 1886 she became engaged to Henry Halliday Sparling, a fellow Socialist comrade. She was married in June 1890 at Fulham Register Office. Her mother did not approve, Sparling's father being a simple Essex farmer. Sparling was given employment as the secretary of the Kelmscott Press. May's marriage did not end happily. Shaw moved in, forming a ménage à trois. May travelled to Zurich with Shaw to attend an International Socialist Workers' Congress without her husband. They eventually separated and divorced.