She was born on September 2nd, 1891 in Skara Stadsförsamling (parish), Skaraborgs County (now Västra Götaland County), Sweden, to Oskar Gustaf (a lawyer) and Ida Jenny (nee Gustafsson) Svendén
She boarded the Titanic at Southampton with her half-brother Kurt Arnold Gottfrid Bryhl and her fiancé Ingvar Enander. They were travelling to Rockford, IL to stay with their uncle, Oscar Lustig who lived at 511 Pearl Street. Kurt, who, unlike Dagmar and Ingvar was emigrating to America, acted as interpreter for them.
After the Titanic struck an iceberg Dagmar and the two men made it to the Boat Deck. Dagmar had been in a hurry and had not put on her shoes. Ingvar had promptly brought with him her1 shoes when he saw her come in her red slippers. They went to the port side of the boat deck accompanied by Henrik Kvillner. Dagmar got her shoes and Ingvar put the slippers in his Ulster pocket. Dagmar didn't remember the number on the boat, but she noticed that it was not even half full when lowered. Looking up she could see Ingvar and Kurt and beside them Henrik Kvillner standing on the deck wearing lifebelts.
Dagmar was probably rescued in lifeboat 12.
Upon her arrival in New York Dagmar wrote to her uncle in Rockford little knowing that he was already in New York searching for her:
Mr Lustig came to New York searching for Dagmar at the Scandinavian Immigrants' Home. However, he was unable to find her (he reported this in a telegram back to Rockford). Fortunately the hospital where Dagmar had been recuperating had also sent a telegram to Rockford telling Dagmar's relatives where she was being cared for. The relatives telegrammed back to Mr Lustig and told him where he could find Dagmar. Eventually they were reunited and travelled on to Chicago (?Rockford), IL on 24 April. However Dagmer was completely broken down and shortly afterward decided to return to Sweden. The White Star line paid for a ticket on the Adriatic which arrived at Liverpool on 12 May. According to the Liverpool Post Dagmar appeared to have recovered but now and then seemed to fall into trance, brought on by some unpleasant memory.
Dagmar finally made it back to Sweden where she later married a teacher, Eric Holmberg and settled in Kungsälv. She died in August of 1969.