Louisa Catherine Johnson Adams (if we consider the USA as Thirteen Colonies)
Louisa Catherine Johnson Adams, wife of John Quincy Adams, was First Lady of the United States from 1825 to 1829. The daughter of the American Consul in London, she was the first First Lady to be born outside the United States, or outside areas that were later to become part of the United States, such as the Thirteen Colonies -- a distinction that was not replicated until 188 years later, by Melania Trump.
Melania Trump (If we consider USA as current USA)
Melania Trump is the First Lady of the United States, married to President Donald Trump. Born in Slovenia, then part of Yugoslavia, she became a permanent resident of the United States in 2001 and an American citizen in 2006. Prior to marrying Donald Trump, she pursued a modeling and business career. After Donald Trump joined the office of President of United States, Melania Trump became second foreign-born First Lady of the United States, following Louisa Adams in 1825 or First foreign born lady if we consider the USA as current USA.