Hi Sam,
Marian Longstreth Morris Thayer was born November 9, 1872 to Frederick Wister Morris and Elizabeth Flower Paul, both representatives of old Philadelphia moneyed families. She never remarried after Titanic and her husband and parents left her very well off. She died in Haverford, Pennsylvania on April 14, 1944 (on the 32nd anniversary of striking the iceberg) of heart failure brought on by arteriosclerotic heart disease and was buried in the Thayer family plot at Church of the Redeemer Cemetery in Bryn Mawr, Pennsylvania.
Her Last Will and Testament (4 pages long) left her estate to her four children and did not mention as many specifics as one might wish to know--but she does speak of real estate, securities, and stocks and bonds. The Will also calls for bequests to her servants Mary Hillier and Margaret Fleming. Margaret Fleming was traveling with the Thayer family on Titanic--but she would receive no bequest as she died before Mrs. Thayer. Mrs. Thayer also requested that "some small sum" be given to any other servants who had been in her employ for a period of 5 years prior to her death.
This is from the Philadelphia Inquirer of April 15, 1944, page 16:
Mrs. John B. Thayer
Mrs. John B. Thayer, widow of John B. Thayer, prominent Philadelphian and Pennsylvania Railroad official, died yesterday on the 32nd anniversary of her husband's death in the Titanic disaster. She was 72.
When the Titanic sunk on April 14, 1912, off Newfoundland after striking an iceberg, her husband, 2nd vice president and director of the Pennsylvania Railroad, was carried to his death, but Mrs. Thayer and her son, John B. Thayer, Jr., were rescued in a lifeboat.
Mrs. Thayer was the daughter of the late Frederick Wister Morris, and lived in Cheswold Lane, Haverford. She had been ill a year. Surviving, besides John, are another son, Frederick M., of Newtown Square, and two daughters, Mrs. H. Hoffman Dolan, of Haverford, and Mrs. H. E. Talbott, Jr., of New York. Funeral services will be held at 5 P.M. Monday at the Church of the Redeemer, Bryn Mawr.
I hope that helps with some of the items you were interested in.
Phillip