She's a sexy lady in white! Scarlett Johansson looked prim and proper when she stepped out in the streets of NYC earlier today before her appearance on the Late Show with David Letterman.

For her promo stop, the new mom donned a lacey pencil dress underneath a tan coat. The superstar may shielded her eyes with an oversized pair of sunglasses -- but she couldn't hide that mega-watt smile of hers!

Things seems to be going swimmingly since getting married to French writer Romain Dauriac and giving birth to their daughter Rose last year.

"[Marriage] takes a lot of work," Ryan Reynolds' ex wife said to Parade magazine recently. "It takes a man who's not only confident in the love that you have for one another, but confident in what he has going on in his own career. He has to be in a field that's completely different from yours."

In the new flick, the Avengers facing a new foe, Ultron, an intelligent robot with the voice of James Spader, who will stop at nothing in an attempt to destroy mankind. Ultron poses a major threat to the future of mankind and it's up to the Avengers to squash his path of destruction!

Iron Man, Thor (Hemsworth), Captain America (Evans), The Hulk (Ruffalo), Hawkeye (Renner), and Black Widow must band together again to save the world!

Avengers: Age of Ultron, written and directed by Buffy the Vampire Slayer's Joss Whedon, slams into theaters on May 1, 2015.