Funny but tough to achieve - George VI and Queen Elizabeth were present at Buckingham Palace on one occassion when the Palace was bombed - but only once and their daughters were both safely at Windsor Castle in fact both Princesses rarely left Windsor and despite propaganda the King and Queen almost never spent the night in London returning to the relative safety of Windsor most nights.
The regent designate until Elizabeth's 18th was Henry Duke of Gloucester.
The succession in 1940 and this is people only born as of 1940 was Elizabeth, Margaret Rose, Henry Duke of Gloucester, Prince William of Gloucester, George Duke of Kent, Prince Edward of Kent, Princess Alexandra of Kent, Princess Mary The Princess Royal, George Viscount Lascelles, the Hon Gerald Lascelles, HRH Princess Arthur of Connaught, Duchess of Fife, Prince Alistair of Connaught, Princess Maud, Countess of Southesk, James Carnegie, Crown Prince Olaf of Norway, Prince Harald of Norway, Princess Ragnhild of Norway, Princess Astrid of Norway.
Desendants of Alfred Duke of Saxe Coburg Gotha and Edinburgh - Carol II of Roumania, Prince Michael of Roumania, Prince Nicholas of Roumania, Princess Elizabeth of Roumania Queen of Greece, Queen Marie of Yugoslavia, King Peter II of Yugoslavia, Prince Tomislav of Yugoslavia, Princess Illeana of Roumania Archduchess of Austria Princess of Tuscany (her six children were Catholic thereby excluded), HIH Grand Duke Vladimir Kyrillovitch of Russia, HIH Grand Duchess Maria Kirilovna of Russia Princess of Leiningeng, Prince Emich of Leiningeng, Prine Karl of Leiningeng, Princess Kira of Leiningen, Princess Margarita of Leiningen, Princess Mechtilde of Leiningen, HIH Grand Duchess Kira Kirilovna of Russia Princess Louis of Prussia, Prince Friedrich Wilhelm of Prussia, Prince Michael of Prussia, Princess Alexandra of Saxe Coburg Gotha and Edinburgh, Prince Gottfried of Hohenlohe-Langenburg, Prince Kraft of Hohenlohe-Langenburg, Princess Beatrix of Hohenlohe-Langenburg, Prince Georg of Hohenlohe-Langenburg, Princess Maria of Hohenlohe-Langenburg, Prince Hans of Shleswig Holstein, Prince Friedrich of Shleswig Holstein, Princess Maria of Shleswig Holstein, Princess Alexandra of Hohenlohe-Langenburg, Princess Irma of Hohenlohe-Langenburg, Princess Beatrice of Saxe Coburg Gotha and Edinburgh Duchess of Galliera (descendants excluded because Catholic)
HRH The Duke of Connaught and Strathearn and so on.