 From 1784, it was noticed that she was courted by Baron Evert Wilhelm Taube af Odenkat, cousin of Hedvig Taube, and from about 1790, they were known to be involved in a serious long term relationship.This affair took place in parallel with the affair of her friend duchess Charlotte and her younger brother Fabian Reinhold von Fersen, and the two women gave each other messages in their letters referring to "F." and "T."
In 1795, she was widowed, and her relationship to Taube took on an official meaning.When duke Charles and duchess Charlotte left Sweden for their European journey in 1798, Sophie Piper declared that she would also go to Germany, but not as the lady in waiting in service of duchess Charlotte, but separately, with baron Taube, a decision she fulfilled.