Trump Jr. exclusively tells Us Weekly. Trump Jr., 36, who is the eldest son of Donald Trump and first wife Ivana Trump, married model Vanessa in November 2006. They are parents to daughter Kai, 6, and sons Donald John Trump III, 4, Tristan, 2, and Spencer, 15 months. This will be Donald Trump's seventh grandchild. Donald Trump Jr.'s younger sister Ivanka Trump, 32, is mom to daughter Arabella, 2, and son Joseph, 3 months, with husband Jared Kushner.