Paul McCartney to Marry Nancy Shevell?

Sir Paul McCartney looks set to embark on his third marriage -- to new girlfriend Nancy Shevell, according to reports.

The Beatles legend -- whose second marriage to Heather Mills ended with a multi-million dollar divorce payout -- has been speaking to his fashion designer daughter Stella about tying the knot -- and she's given it her blessing.

A source tells Britain's News of The World newspaper, "Paul's utterly enchanted with Nancy and he’s already rolling the idea of marriage around in his head.

"He adores everything about her. He thinks she’s 'The One' and told Stella as much.

"He said, 'What would you say if I asked Nancy to be the next Mrs McCartney?' And she joked back, 'At least she’s financially independent.'

"The whole family thinks Nancy’s great—a vast improvement on Paul’s last love interest."

Paul, 66, married Linda Eastman in 1969; she died of breast cancer in 1998. He married Heather Mills in 2002; and divorced in 2008.

Socialite Nancy is wealthy in her own right and is pushing through her own divorce to US lawyer Bruce Blakeman.

The source added, "Nancy and Bruce have been separated a long time but her relationship with Paul has spurred them on to finally dissolve the marriage.

"They've moved on with their lives and Bruce approves of Paul. It's all amicable."

Paul and Nancy, 47, spent last week cosying up on a US road trip down Route 66.

"They've been with each other 24/7—a perfect way to see if they’re suitable for marriage," the source said. "Paul's not about to rush into anything, but he's happier than he's been for years. They've got so much in common. He knows Heather was a mistake, although he loves their little one Bea more than anything, and won't be put off by a bad divorce experience.

"Nancy and Paul share so much in common. There's a lot of history there – big connections that go way back."