Richest baby in the world, Maxima, debuts on Facebook?

Facebook co-founder Mark Zuckerberg and wife Priscilla Chan, 30, welcomed their baby daughter earlier this month.

The heir to his $46 billion-dollar fortune, Maxima Chan Zuckerberg, has made her Facebook debut.

Already a daddy's girl, Mark shared a touching photograph of her on Tuesday (Dec 8).

Captioned simply 'full of joy with little Max', the picture shows an emotional Zuckerberg nestling the tiny baby girl in his hand as they look into each other's eyes.

The father and daughter pair appear to be lying on a carpeted floor, with a pillow propped behind the 31-year-old billionaire.

Baby Max's discarded onesie is just in shot.

The image, which shows a happy-looking Max kicking her feet in the air while wearing just a diaper, may suggest the Silicon Valley tycoon has already got his hands dirty and done his first baby changing.

The post has already earned thousands of Likes and comments after being shared on Facebook.

In replies to comments on the pictures, notoriously private Zuckerberg gave some small insights into his new family life.

'Everyone is doing great', he told one fan who asked how his wife Priscilla and his daughter were getting on.

The couple used the birth to reveal plans to give away the vast majority of their private wealth to good causes.

The couple pledged to give away his fortune to make the world a 'better place' for baby daughter Maxima and others.

In a letter to Maxima posted on his Facebook page, Zuckerberg and wife Priscilla Chan said they were going to give away 99 per cent of their company shares - estimated value $45 billion -  during their lives in an effort to make a happy and healthy world.

"Max, we love you and feel a great responsibility to leave the world a better place for you and all children. We wish you a life filled with the same love, hope and joy you give us. We can't wait to see what you bring to this world," the letter said.

Zuckerberg will "gift or otherwise direct" nearly all his shares of Facebook stock, or the after-tax proceeds of sales of shares, to further a mission of "advancing human potential and promoting equality" by means of activities for the public good, the California-based social network said in a filing with the US Securities and Exchange Commission.

Zuckerberg plans to take two months' paternity leave to be a dad.

"Studies show that when working parents take time to be with their newborns, outcomes are better for the children and families," Zuckerberg said in an earlier post on his Facebook page.

Beginning with the New Year, dads working full-time for Facebook anywhere in the world will have the option of taking four months' paid leave.

All new dads working for Facebook outside the US currently get a minimum of four weeks' paternity leave, with more time offered in locations where required by local law, according to Facebook.

Maternity leave offered to Facebook employees around the world is already four months, and the benefit was available to both moms and dads in the United States.

Facebook also gives a $4,000 bonus for parents to help meet the needs of new babies.