It was an unprecedented move for a first lady and one that showed Melania's ownership of the cause.

The new Take It Down Act provides protections for victims of revenge porn and it marked her first major legislative success.  

For a first lady to add her signature is highly unusual - it is the president that signs bills into law - but Melania had championed the legislation and met with lawmakers on Capitol Hill to lobby for it. 

After signing the bill on Monday in the Rose Garden, Trump encouraged his wife to do so as well, handing over the binder featuring the law and telling her to go ahead. She smiled as she picked up a white pen to add her name underneath his. 

The president also praised his wife's work on the issue. 

'Honey, you've done amazing,' he said, adding that when he heard of the legislation: 'I said, it sounds like a tough one, and yet a very important one, and you got it done. So I congratulate you.'

And he noted when he talked to Russian President Vladimir Putin earlier Monday: 'Putin just said they respect your wife a lot. I said, 'What about me?' They like Melania better.'

Melania spoke first at the Rose Garden signing ceremony. It was a rare appearance for her at a White House event.

She called the legislation a 'national victory that will help parents and families protect children from online exploitation.' 

'This legislation is a powerful step forward in our efforts to ensure that every American, especially young people, can feel better protected from their image or identity being abused,' she continued. 

And she criticized artificial intelligence and social media, calling it the 'digital candy for the next generation.'

'Sweet, addictive and engineered to have an impact on the cognitive development of our children,' the first lady explained. 'But unlike sugar, this new technologies can be weaponized, shape beliefs and sadly affect emotions and even be deadly.'

The bill had the support of both Republicans and Democrats and the first lady cheered its bipartisan nature. 

'Thank you all for coming together to prioritize people over politics,' she said.