Ehrenström was born in Germany to the Swedish commendant of Stralsund in Swedish Pommerania. She became a lady-in-waiting to the queen, Sophia Magdalena of Denmark, at the age of seventeen in 1790, a position she kept until 1803. She was educated in singing by the singer Christoffer Christian Karsten, in piano playing by the composer Vogler and in drama by the actor Jacques Marie Boutet de Monvel and was admired as a singer, a piano player and as a painter of landscapes and miniatures, was seen as a great culture personality, and made friends with dramatist Carl Gustaf af Leopold.
In 1800, she was elected to the Academy of the Free Arts and as an honorary member to the Royal Swedish Academy of Music in 1814. Between 1815 and 1831, she founded and managed a girl's school. She married Colonel Ehrenström in 1816. In 1826 she published a book about writers, theatre, music, painting and sculpture. She is most known in history for her memoirs, written in French, a large, often quoted and valuable source about the contemporary period, now kept at the Swedish Academy.