Märta Helena Reenstierna, also von Schnell, known as Årstafrun, was a Swedish diary writer
Märta Helena Reenstierna was the daughter of lieutenant Abraham Reenstierna and Catharina Maria von Köhler.
Her diaries were written in the period 1793–1839, and are kept at the archives of Nordiska museet in Stockholm. They were published in 1946–1953 as Årstadagboken (The Årsta Diary). They are considered as a valuable cultural historical document of the everyday life of the people at a Swedish manor of her epoch.
However, the spouses seem to have had an active social life, as in retrospect, she described her spouse as: "formally a resplendent host and an brilliant escort, he is now approaching is 60th birthday and now resembles a sour and sad old man, who detests society and activates himself only by tending to economical matters".
Reenstierna was a personal friend and benefactor of Bellman, whom she helped financially on several occasions. Årsta was a relatively large estate with, among other things, cultivated tobacco.
Reenstierna continued with the diary and the managing of the estate until she became blind in 1839. Märta Helena Reenstierna was portrayed in the novel På Årstafruns tid (English: The times of the Årsta lady) by Lars Widding (1969).