And Nicholl says there's a side of Kate Middleton - newly engaged to Prince William - few people outside royal circles know.
"I think she's an awful lot of fun, and she can drink Prince William under the table," Nicholl told "Early Show" co-anchor Erica Hill Wednesday. "I've been at nightclubs with her where I've seen her (drinking with William) and do shot after shot, and she's the one (left) standing and William is the one who's looking totally out of it. So, she's quite a partier.
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"I know people think she is very demure and a bit of a wallflower, which she is. But I've always said, don't underestimate this girl. There's a lot to her.
"But she is a lot of fun, and I think she has a reputation being a bit of a Plain Jane. And there's just a lot more to her. Here in England, we haven't seen that much of her. That press conference (with Prince William) at St. James's Palace yesterday was the first time that we've heard her speak, that we've seen her picture, that we've seen her take the stage. … I think she did an amazing job."
Nicholl says she thinks the session "was better than what we were expecting. I certainly didn't expect her to be so confident. I spoke to her before she went up on the stage, and she said she has butterflies. And of course was very, very nervous, but I think she handled it so well. And I know there's always going to be the (William's late mother), but I think Kate has a confidence about her, and that's largely because the palace had introduced her to royal life from a very early start in their relationship."
"It's going to be hard," Nicholl added, for Middleton to come out from under Diana's shadow, but William will "help hugely." Nicholl says she hopes people give Middleton the leeway to be her own person.
The perception of the Royal Family will also change - for the better - due to Middleton, Nicholl predicts.
"She is middle-class, she's not an aristocrat. She's a real breath of fresh air for the House of Windsor. So, absolutely, she's going to change it, but I think … for the better. She and William … (are) the future of this monarchy, of this House of Windsor. They're going to take it forward into the 21st century, and I think they'll do a great job."
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