Tiffany Trump, the Donald's fourth child and the only member of the immediate family who shares his hair color, turns 15 today. Also celebrating: Sacha Baron Cohen is 37. Ashanti is 28. Paul Simon turns 67. Kelly Preston is 46. Van Halen's Sammy Hagar turns 61. George Bush's cousin, Access Hollywood's Billy Bush, is 37. George Bush's former spokesman, Ari Fleischer, is 48. Modeling legend Beverly Johnson is turning 56. Modeling honcho Ivan Bart is 45. Art dealer William Acquavella is 71. And billionaire heir Thomas Tisch is 54.