Stepping out to promote her new movie “Clear History,” Kate Hudson showed up at “The Tonight Show with Jay Leno” last night (July 31).

The “Fool’s Gold” gal discussed how she and her main man Matt Bellamy disagreed on the sex of their son Bingham back when he was still in the womb.

“There was no question in my mind that it was a girl. Because it was completely different, it was a totally different pregnancy, I carried different, he felt different. My mom and I, we knew it was a girl… Matt totally was like, ‘It’s a boy.’ He knew the whole time he was like, ‘Ah, I think it’s a boy.’”

As for the Royal Baby fanfare over in London, Kate shared, “Oh that was insane actually. You can’t help but follow it because it’s on every news channel. Like, that’s all you saw. It was the longest labor on news, it literally was full coverage.”

And though she’s never met the Royal Family, Hudson told of a time that her father Kurt Russell let them stay at the family vacation home. “Prince William and Prince Harry actually stayed at our house in Colorado when they were kids. I remember we were all in LA and they were staying with their mom at the time. And we get this phone call at the house, and my dad gets to the phone. I think it was Prince William, calling my dad to ask if he could use the ATVs… And when my dad got off the phone he said, ‘That’s a really well-raised boy!’”