Minona Maria Theresia Selma Loisa Cornelia von Stackelberg

According to a hypothesis exposed and sustained during the '50's, (Kaznelson, "Beethovens ferne und unsterbliche Geliebte", Zurich, Standard Buch Verlag - 1954), the relationship between Beethoven and Joséphine continued after her second marriage and had an intimate epilogue in Prague in July of 1812; the letters known as “to my immortal beloved”, are considered to have possibly been written for Joséphine. A final analysis of the paternity of Joséphine's last daughter, Minona, born Stackelberg on 9th April 1813 is under question.
Indeed, the Baron Stackelberg had been in Estonia since 1810, where he was dwelling with another woman. He only visited Joséphine twice, in January and October of 1812. A few therefore find it easy to reach the conclusion that Minona was not the daughter of Stackelberg.
The hypothesis is not pure conjecture, but also cannot be proven. If anyone attempted to attach any certitude to the matter, the contrary is also true: no one can contemplate this possibility. The descendants of the Brunswick family, today residing in Hungary, always deny the possible relationship between the musician and the illegitimate daughter of Joséphine.
See: http://www.lvbeethoven.com/Famille/FamilyTree-Minona.html