Marie Johanna Schiff

The youngest daughter of Alfred Schiff was born in 1877. She was presumably named Johanna after her paternal grandmother Johanna Wollheim. I have found nothing about her early life, but in July 1897 she married Hermann Richard Wächter of Hamburg in a suspiciously quiet ceremony at St George's, Hanover Square. There was a son born to this marriage, George Ernest Richard Harry Wächter; presumably George after his paternal grandfather, Ernest after his maternal great uncle and uncle, and Richard after his father. The marriage appears to have been short lived, and ended at some time in divorce, as by 1905 in her father Alfred Schiff's will, Marie is described as being the wife of Friedrich - or Fritz - von der Marwitz, and her first husband is obviously seriously out of favour, so much so that if young George Wächter were to live with his father then he would not receive any inheritance from his grandfather. I do not know what became of George's father, though he may possibly be the German soldier Hermann Wächter who died during the First World War on 18th December, 1914, on active service in the German army. As for George, he appears not to have married and died on 19th July, 1945 at Beaulieu-sur-Mer in the south of France, between Nice and Monaco.
[Postscript September 2018: George it seems did indeed marry, to the Brazilian Plàcida Martins. Soon after George's death she married Alvaro Lyra Da Silva of Rio de Janeiro by whom she had a daughter.]

Marie appears to have married Baron Friedrich Wilhelm Edmund von der Marwitz, a member of a well known and distinguished German noble and military family from Prussia, at some date prior to 1906. Their son, and probably only child, was Friedrich Alfred von der Marwitz, born at Frankfurt am Main, on 11th November, 1907. His names were presumably after his father, and maternal grandfather. Marie and her husband, the baron and baroness, appear to have settled at some time in England, where Marie eventually after the First World War reclaimed her British nationality and her husband was naturalised. Their surname was transformed to de Marwicz, giving it a Franco-Polish flavour, and indeed they seem to have lived a great deal in France, in Paris and Monte Carlo. Friedrich - now Frederick - wrote books in the 1920s heavily critical of Germany's role in the Great War. He died in Monte Carlo on 16th April, 1944, before the Second World War ended, and just over a year before the death of his stepson. Marie Johanna did not long outlive him: she died in England on 25th February 1948. 
[Postscript January, 2017: Marie divorced her husband and reclaimed her British nationality in order to receive her generous inheritance from her uncle Sir Ernest Schiff. She then promptly remarried her ex-husband.]

Frederick Alfred de Marwicz appears to have been educated in England, was also naturalised as British, and attended Pembroke College, Cambridge. He is known as an ice hockey player, also known as Frank or Bibo, and played for Great Britain as a left wing from 1930 to 1934. He served in the Second World War in the Scots Guards, rising to the rank of Captain. He was the third husband of Diana, born Frances Walkington, daughter of Thomas Walkington and Edith Mary Faulkner. She was born in Yorkshire in 1913. Her first husband was the Scot Anthony Gilbert Thorburn in 1935. In 1941 she married David Behar, whose name suggests he was a member of a Sephardi family, and in 1951 she married Frederick de Marwicz. Two daughters were born, Marie in 1952, who I believe lives in west London, and Diana in 1953, who I believe lives in Torbay. Frederick died in 1990.