She was the daughter of a minor German aristocrat who worked as a schoolteacher. She claimed that she knew nothing about Reinhard Heydrich’s crimes committed while he was head of the RSHA, or Reichssicherheitshauptamt, Reich Main Security Office. Lina von Osten met the then Naval Lieutenant Heydrich on December 6, 1930, at a gala hosted by the school rowing club in Kiel which Lina attended. There was an immediate attraction and after only a few dates the couple became engaged on December 18, 1930. Lina von Osten was nineteen at the time. After Heydrich’s dismissal from the navy, they married at a small church in Grossenbrode on December 26, 1931. Lina Heydrich gave birth to two sons, Klaus (born June 17, 1933) and Heider (born December 23, 1934). By the late 1930s, the duties of Reinhard Heydrich led him to work long hours and often be away from home. This left Lina at home with the children and having to run the household alone. This placed a serious strain on their marriage that nearly resulted in divorce. However, the reconciled Heydrich couple had another child, a daughter named Silke (born April 9, 1939). Reinhard proudly showed off his baby daughter and they had a close relationship. Their fourth child, a daughter named Marte (born July 23, 1942) was born shortly after Reinhard Heydrich‘s death.
Her eldest son, Klaus, died as a result of a traffic accident on October 24, 1943. On that day, Klaus was cycling with his brother Heider Heydrich in the courtyard of the Castle Jungfern-Breschan. Seeing that the gate to the street was open, Klaus rode out onto the street where he was struck by a small truck coming down the road. Klaus died from his injuries later that afternoon.
She wrote a memoir, Leben mit einem Kriegsverbrecher (1976) (Life with a War Criminal). She spoke with several authors, sent in letters of correction to many newspapers, and defended her late husband
, Reinhard Heydrich, until her death in Fehmarn at the age of 74 on August 14, 1985.