Well, she’s the head of state of a number of countries and the commonwealth. Represents political and social continuity. This has historical significance, which might be of interest to some of the readership. She was trained as a mechanic and is one of the few old enough to have been an adult in the war. Her death might, maybe will, be responsible for a number of commonwealth states changing their structure of government.

Bit more significant to RL than one might think.