Question: What is the date of death of Dhasanawalaya Sornsongkram's mother?
Sentence (from "Dhasanawalaya Sornsongkram"): Than Phu Ying Dhasanawalaya Sornsongkram , née Dhasanawalaya Ratanakul Serireongrit (born 11 November 1945 in Switzerland), is the only daughter of Galyani Vadhana, Princess of Naradhiwas and niece of King Bhumibol Adulyadej.
Relevant evidence: Yes