Princess Adelaide of Saxe-Meiningen (1891-1971) married Prince Adalbert of Prussia. How was she related to the Princess Adelaide of Saxe-Meiningen who married the future William IV of England?
Queen Adelaides brother Duke Bernhard II was the Great Grandfather of Princess Adelaide, Princess Adalbert.
Duke Georg I Saxe Meiningen - Princess Adelaide. m. King William IV
Duke Georg I of Saxe Meingen - Duke Bernhard II - Duke Georg II - Prince Friedrich - Princess Adelaide m. Prince Adalbert Prussia