WASHINGTON — Patricia Knatchbull, a cousin of Prince Philip who survived an Irish Republican Army bombing that killed her father and teenage son, died June 13 at her home in southeast England. She was 93.

Mrs. Knatchbull, titled Countess Mountbatten of Burma and known as Lady Patricia, was the elder daughter of the British World War II military leader Lord Louis Mountbatten, who died in the 1979 bombing aboard his fishing boat off the coast of County Sligo in western Ireland. The attack also claimed the lives of her teenaged son; her mother-in-law, who was 83; and a 15-year-old deckhand.

Mrs. Knatchbull, her husband, and another son were badly wounded but recovered.

Mrs. Knatchbull, while in the water, said she remembered advice her father had given after he was once shipwrecked: that she should hold her nose and mouth to prevent drowning. She suffered a shattered leg, cuts from splinters, and facial trauma that required 120 stitches in her face, including her eyeballs. She later called the scars ‘‘my IRA facelift.’’

She spent much of the rest of her life supporting charities for children and another that helps parents cope with grief.

Part of her own emotional healing involved not succumbing to hatred of the attackers. ‘‘If you are bitter, it consumes you, your family, and the people around you,’’ she told the British newspaper the Daily Telegraph in 2008. ‘‘If my father had survived he would have felt the same way.’’

A descendant of Queen Victoria, Mrs. Knatchbull was close to the royal family and a lifelong confidante of Queen Elizabeth; she was also Prince Charles’s godmother. Charles, in a statement, said he had ‘‘known and loved [her] ever since I can remember. She played an extremely important part in my life.’’

Mrs. Knatchbull leaves six children; her sister; and 18 grandchildren. Her husband died in 2005.