WASHINGTON (Reuters) -Ivana Trump, the first wife of former U.S. President Donald Trump and the mother of his three oldest children, who helped her husband build some of his signature buildings including Trump Tower, has died at age 73, Donald Trump said on Thursday. “I am very saddened to inform all of those that loved her, of which there are many, that Ivana Trump has passed away at her home in New York City,” Trump said in a post on the social medial platform Truth Social. The couple married in 1977 and divorced in 1992. They had three children together: Donald Jr., Ivanka and Eric. “Ivana …