MacKenzie Bezos, who just months ago divorced the world’s richest man, has pledged to give away half her fortune to charity.

The former wife of Amazon founder and chief executive Jeff Bezos is one of the 19 new signatories to the Giving Pledge who have promised to donate more than 50% of their wealth, the organization said.

“I have a disproportionate amount of money to share,” MacKenzie Bezos said in a letter released Tuesday. “My approach to philanthropy will continue to be thoughtful. It will take time and effort and care. But I won’t wait. And I will keep at it until the safe is empty.”

Bezos’ personal fortune is worth nearly $37 billion, making her the 22nd-richest person in the world, according to the Bloomberg Billionaires Index.

The Giving Pledge was created by billionaires Warren Buffett and Bill and Melinda Gates in 2010. It asks the world’s wealthiest people to promise to give away half their wealth during their lifetimes or in their wills.

Bezos’ former husband, who is worth an estimated $114 billion, has not yet signed the pledge but tweeted his support for his ex-wife’s decision.

“MacKenzie is going to be amazing and thoughtful and effective at philanthropy, and I’m proud of her,” he said on Twitter.

 

 

​Other billionaires who have signed the Giving Pledge include Elon Musk, oil baron T. Boone Pickens, Michael Bloomberg, Richard Branson, and WhatsApp co-founder Brian Acton and his wife, Tegan.