Was Princess Diana really Winston Churchill's granddaughter?

In the months before Lady Diana Spencer’s wedding to the Prince of Wales, I heard in a TV news report that Diana was the granddaughter of Sir Winston Churchill. I brought this up in a couple of SDMB threads, because it is a “fact” that, if not important, is very interesting: Churchill’s mother was a Virginian, so, if and when Diana’s son William comes to the throne, he will be the first British monarch with American ancestors!

But several posters asserted that Diana’s descent from Churchill was pure UL, based on confusion of the facts – apparently there was a marriage between a Churchill and a Spencer but it was in the 19th century.

I looked up some web pages with short biographies of Diana, but none mention here genealogy further back than her parents. Does anybody know?

And, just for the record, Churchill’s mother was born in Brooklyn, not in Virginia.

Ok, here’s the geneological record of Princess Diana.

http://www.idreamof.com/diana_tree.html

Her great-grandmother’s family apparently was American, but she is not the granddaughter of Winston Churchhill. Her grandparents were Albert Spencer, Cynthia Hamilton, Edmund Burke-Roche, and Ruth Gill.

To add: the Churchills and the Spencers are related, if you go back far enough. Charles Spencer (1706-58) was both 3rd Duke of Marlborough (the 1st Duke of Marlborough was John Churchill, by the way) and 5th Earl of Sunderland - Sir Winston Churchill is his descendent. John, 1st Earl Spencer (1734-83) was Charles’ nephew - Diana’s family is descended from John. Confused enough yet?

Oh, and here’s a family tree (very tiny print on Adobe page):
http://www.althorp.com/spencer-family/familytree.pdf

No, you are thinking of Jesus’s mother, Mary.

Clementine Hambro, the youngest bridesmaid, is a great-granddaughter of Winston Churchill. She was the little blonde bridesmaid. A lot of the balcony pictures have her right next to the couple, and there’s a famous photo of the wedding party standing in a hallway of Buckingham Palace, with Lady Diana saying encouraging things to her before the wedding, with the Queen standing behind them, looking a little bit worried. I think a lot of the news reports at the time mentioned her, sometimes incorrectly describing her as the granddaughter of Winston Churchill. It’s not a far stretch to think that a over-enthusiastic, sleep-deprived reporter took the mistake one step further and described the new princess as a granddaugher of Churchill.