Question: What is the date of death of Heidi Blomstedt's mother?
Sentence (from "Heidi Blomstedt"): She married the architect Aulis Blomstedt, and they had four children: Juhana Blomstedt (1937–2010), Petri Blomstedt (1941–1997), Anssi Blomstedt (b. 1945) and Severi Blomstedt (b. 1946).
Relevant evidence: No