Gala.de has a review of her life:

The Serbian Orthodox Church of St Sava hasn't seen mourners like these at the funeral of Princess Margarita of Baden. Many distinguished guests came to London on January 15th in Farnham to pay their last respects. The ceremony was a kind of royal family reunion, because Princess Margaritas family ties to the reigning and former reigning houses of Europe go far.
Margaritas mother Theodora was a princess of Greece and Denmark, and a sister of Prince Philip Mountbatten, the husband of Queen Elizabeth II Theodora married 1931 Berthold of Baden, whose mother, Marie Louise, a great-great-granddaughter of King George III. was from England. That made her also a princess of England and Ireland. Tyra, Marie Louise's mother was a daughter of the Danish King Christian IX., Her father was from the House of Hanover.
These far-reaching royal relationships made Margarita a great-great-great-granddaughter of Queen Victoria of England, niece of Prince Philip and cousin of Prince Charles. Christian IX, who was known as "father of Europe", is also the great-great-grandfather of Queen Margrethe of Denmark and her two sisters, of whom the youngest, Anne-Marie, in turn married into the Greek royal family: she is the wife of King Constantine.
Mourners attending the service at St. Sava were, alongside Margarita's two children and her immediate family, her Danish-Greek uncle, Prince Philip, the Danish-born Queen Anne-Marie of Greece, her nephew, Crown Prince Alexander of Yugoslavia with his family, as well as Princess Sarvath of Jordan and the representatives of the House of Baden, including Margarita's brother, Margrave Max von Baden with his wife Valerie
The late princess was born in 1932 in Salem. She moved to England in the 1950s. There she met her future husband, Prince Tomislav of Yugoslavia. The couple married in 1957 in Salem, had two children and managed a farm in Sussex. The marriage lasted only until 1981. Then Margarita took back her maiden name, "Baden" and spent many years working in the hospital service in London, where she was known as "Nurse of Baden" ("Sister of Baden"), reported the British "Telegraph". The princess was a frequent guest at royal celebrations at home and abroad, most recently she was at the wedding of Prince William and Kate Middleton in 2011.
Margarita of Baden is to be buried at her birthplace in Salem.