Read this: Victoria's father was Prince Edward, Duke of Kent and Strathearn, the fourth son of the reigning King of the United Kingdom, George III. Until 1817, Edward's niece, Princess Charlotte of Wales, was the only legitimate grandchild of George III. Her death in 1817 precipitated a succession crisis that brought pressure on the Duke of Kent and his unmarried brothers to marry and have children. In 1818 he married Princess Victoria of Saxe-Coburg-Saalfeld, a widowed German princess with two children—Carl (1804–1856) and Feodora (1807–1872)—by her first marriage to the Prince of Leiningen. Her brother Leopold was Princess Charlotte's widower. The Duke and Duchess of Kent's only child, Victoria, was born at 4.15 a.m. on 24 May 1819 at Kensington Palace in London.

What year did Princess Charlotte of Wales get sick?
What is the answer? (If it cannot be answered, return "unanswerable")
unanswerable