Elizabeth L. Post died in Naples, Fla., on April 24, surrounded by her family. She was 89.

Libby was born in Englewood, N.J., on May 7, 1920, the third of Allen and Bess Lindley’s three children. She lived in Englewood until 1941, when she married George Cookman, who was killed in action in the Pacific in 1943. Libby then married Bill Post in 1944, with whom she shared the next 65 years of her life in a wonderful, loving marriage which, along with her children, was the central element of her life, and was a source of inspiration to all who knew them. Lib and Bill and their growing family lived in Bogota, Colombia, in the early 1950s, then moved to Rye, N.Y., where they raised their four children, then on to Waterbury Center, Vt., then to Marathon, Fla., and finally to Bentley Village in Naples. In each place they lived they created a wonderful life for themselves and made lifelong friends who were a great source of pleasure to them through the years.

Libby was the granddaughter in law of Emily Post. In the early 1960s she assumed responsibility for carrying on the Post family tradition of writing and teaching about etiquette. Libby quickly became, and remained for the next 30 years, America’s leading authority on etiquette. Six times she revised and modernized the classic Etiquette originally written by Emily Post. She authored books on weddings, children’s etiquette, entertaining and others, and she was in great demand on television and radio shows where the ideas of an expert on etiquette were needed. In the early 1990s Libby cut back on her responsibilities as an author and authority, yielding to her daughter in law Peggy, and a little later, to her daughter Cindy, her son Peter and her daughter in law Tricia. Those four have revived the Emily Post Institute and continue to this day as the country’s leading etiquette writers, teachers and experts. Libby was extremely proud of this succession to a fourth generation of Posts working in the etiquette field, and was most especially proud that now, a fifth generation has joined the firm, in the persons of Libby’s grandchildren, Anna Post, Lizzie Post and Dan Senning.

Libby was a gifted artist. Her paintings, especially her later watercolors, grace the walls of her family’s and friend’s homes, as well as many collectors who purchased her works at the various art shows at which she exhibited over the years. She was generous about donating works to charity auctions where her paintings always sold well. Libby was also an accomplished golfer and a spectacular fisherman. One year, she caught the largest tarpon caught by a woman in the United States that year. She was particularly proud of the day she and Bill each registered a so-called grand slam on the flats of the Florida Keys, a rare feat for one person, much less for two in the same boat on the same day. Libby and Bill were for many years avid scuba divers and made numerous trips to exotic parts of the world to pursue the clearest waters and the most colorful fish.

Libby and Bill and their family enjoyed summers on the Vineyard for many of the 65 years of their marriage.

Libby was a straightforward, practical lady who could be counted on to say what she thought, and her advice was always worth listening to. She was the matriarch of a large family over which she presided with grace, dignity, caring and loyalty. The large family gatherings at Christmas at Lib and Bill’s house in Waterbury, Vt., were family highlights every year. Libby will be greatly missed by all who knew her.

She is survived by her wonderful husband, Bill, her four children and their spouses, Allen Post and Peggy, Bill Post Jr. and Maureen, Cindy Senning and John and Peter Post and Tricia. She is also survived by her eight grandchildren, Casey and Jeep Post, Peter Post and Jill Ravey, Dan and Will Senning, and Anna and Lizzie Post, and her great-grandson, Alexander. She was predeceased in 1987 by her grandson, Paul. She is also survived by her niece, Betsy Lindley Bird, and her nephews Dan Lindley and Pete Lindley, and by numerous great nephews and nieces.

Libby’s family wishes to express its gratitude to the wonderful nurses and staff at the Bentley Extended Care Facility who provided such good and tender care during her last weeks. They are truly compassionate and professional people.