Mrs. Pennoyer, the mother of six, a grandmother of 28 and a great-grandmother of 31, lived in the English-Norman styled home on an estate called "Round Bush" in Locust Valley. Born into a family whose name was synonymous with international banking, immense wealth and philanthropy, she nevertheless lived a private life.

In a rare interview in 1983, Mrs. Pennoyer, who shared her father's great desire for privacy, described somewhat reticently the privileged childhood she had, especially the summers she spent on the Morgan estate on East Island, off Glen Cove.

Mrs. Pennoyer met her husband, [Paul], because of his friendship with her brother Junius. Both men graduated from Harvard in 1914. The couple were married in 1917, and Pennoyer went off to World War I as an artillery officer in the American Expeditionary Force. When Mrs. Pennoyer's mother died in 1925, she became more involved in her father's well-being, while overseeing her own growing family.