Question: What is the date of death of Johann Christian Friedrich Hæffner's wife?
Sentence (from "Elisabeth Forsselius"): Gertrud Elisabeth Forsselius née "Forsell", also called Forselia, later known as Elisabet Haeffner and Elisabet Fahlgren (23 January 1771 – 15 February 1850), was a Swedish stage actress and opera singer.
Relevant evidence: Yes