Largest Age Difference between Siblings

[JR76]

Duchess Christina D'Otrante (1939-) and Countess Charlotte de Roquette-Buisson (1940-) are respectively 37 and 38 years younger than their oldest brother, Count Erik von Rosen (1902-1967). Another one of their older siblings was Princess Elsa Bernadotte (1904-1991) who was the first wife of Prince Carl jr of Sweden.

 

[Duc_et_Pair]

Prince Alexander of the Netherlands, the Prince of Orange, Hereditary Grand-Duke of Luxembourg (1851-1884) and Princess Wilhelmina (1880-1962), later Queen of the Netherlands. Age difference 29 years.

Princess Beatrix of the Netherlands (1938) and Alexia Lejeune-Grinda (1967), age difference 29 years as well.

 

[Biri]

Princess Alia bint Hussein - born 13 February 1956 (mother: Sharifa Dina bint Abdul-Hamid)
Princess Rayiah bint Hussein - born 9 February 1986 (mother: Lisa Najeeb Halaby - Queen Noor)

Father of both: Hussein bin Talal, King of Jordan

30 years minus 4 days'age difference.

Three days after Rayiah's birth her half-nephew, Prince Hussein Mirza celebrated his 5th birthday.