Catherine, Duchess of Cambridge, meets actress
Reese Witherspoon on July 10, 2011. (Reuters)

The 'Sweet Home Alabama' actress and husband Jim Toth welcomed their little boy Tennessee James into the world last month and the royal couple - who Reese met when they visited Los Angeles last year - were among the first to send a gift and a handwritten note.

Reese's 'Water for Elephants' co-star Robert Pattinson, who hid out at her California ranch following his break-up with Kristen Stewart, also sent a lavish gift, a cradle from Posh Tots worth almost $2,000.

A source told America's Star magazine: "Rob was one of the first to call and he even promised unlimited babysitting services. The baby is the toast of Hollywood."

Reese - who has two children, Ava, 13, and Deacon, 8, from her marriage to Ryan Phillippe - previously joked she was upset not to be invited to William and Catherine's wedding as she had asked them to go to hers.

Speaking before the pair married, she said: "I can't even contain my enthusiasm for the royal wedding! I'm kind of bummed I'm not invited to the royal wedding. My girlfriend asked me if I was invited. Well, no, but I invited them to my wedding!"