Mary Isabelle Gebhard Neilson (May 29, 1857 – May 14, 1928)[1] was an American society leader during the Gilded Age in New York City.
Her father joined the family firm in 1845, by which time they had expanded their mercantile business and developed interests in banking and rail-road stocks.
[2] Her brother, Frederick Gebhard was known for his relationship with Lillie Langtry, a society beauty previously known for her affair with Edward, Prince of Wales.
[5] Her maternal grandfather, Thomas E. Davis, was a wealthy New York property developer who made provisions in his will for Isabelle and her brother to receive incomes from his estate until they were 30, at which time the title of the investment would be transferred to them.
[6] Her brother Frederick found himself in reduced circumstances, eventually starting an unsuccessful venture selling fine wines, and needed to borrow money from Isabel.
"[31] He died several months later in July 1887 of Bright's disease while staying at the home of his father in Far Rockaway on Long Island.
[15][32] Isabelle, who did not remarry, died of cerebral hemorrhage at her apartment in the Plaza Hotel on May 14, 1928, and her funeral was held at St. Patrick's Cathedral and she was buried in the family vault in St Mark's Church in Manhattan.