Joan Rivers, who dated Spiros Milonas in the early ’90s, is thrilled his daughter, Claire, had a baby girl in November, even though the father, White House budget director Peter Orszag, got engaged last month to ABC newsgal Bianna Golodryga. “She [Claire] is 39. Leave her alone,” Rivers told us. Claire’s biological clock was ticking. “I hope she has another one. I’m sorry it wasn’t twins,” Rivers said. The comic remembers Claire as a “smart as a whip” Yale grad who is fluent in Greek, “and she has a great body. She looked great in a bikini.”