Jessica Simpson Is on a Sexy Style Streak in NYC After Revealing 100-Pound Weight Loss

Jessica Simpson is fit and fashionable!

The singer, 39, pulled-off the chicest day-to-night outfit combo in NYC on Tuesday, after revealing on Instagram that she lost 100 pounds in six months just a few hours before.

Simpson first stepped out in a bright orange peacoat, layered over a black long sleeve top and paired with oversized sunglasses, black stilettos and a velvet and leather tote bag. The designer posed next to a Macy’s store sign for an Instagram picture that perfectly captured the fall outfit.

“I am feeling very blessed and inspired getting to shop and work at the same time with @macys,” Simspon (whose self-titled clothing and accessories line is sold at the department store giant) captioned the post.

Then later that day, the “With You” singer slipped into a curve-hugging little black dress, which featured ruching, a plunging neckline and a hint of lace detail.

Raymond Hall/GC Images; Gotham/GC Images
Raymond Hall/GC Images; Gotham/GC Images

“NYC Ladies’ Night,” she wrote in a sexy Instagram post.

Fans celebrated Simpson’s weight loss — and her fashion-forward back-to-back looks — in the comment section.

“You look like such a boss,” one user wrote. While another sweetly commented, “You look great these days! Not that you didn’t before.”

Raymond Hall/GC Images
Raymond Hall/GC Images

Just hours before sharing outfit pictures, Simpson announced on Instagram that she lost 100 pounds six months since welcoming daughter Birdie Mae, on March 19.

RELATED: Jessica Simpson Calls Being a Mom of Three ‘More Than a Full-Time Job Right Now’

“6 months. 100 pounds down (Yes, I tipped the scales at 240 😜),” Simpson captioned a two-photo slideshow featuring both herself solo and one snap with her 6-month-old baby girl.

Jessica Simpson/ Instagram
Jessica Simpson/ Instagram

“My first trip away from #BIRDIEMAE and emotional for many reasons, but so proud to feel like myself again,” Simpson continued. “Even when it felt impossible, I chose to work harder.”

On Thursday, the star posted an adorable video of Birdie with husband Eric Johnson and their older children, Ace, 6, and Maxwell, 7. Seemingly missing her family, Simpson captioned the Instagram post, “Meanwhile, back at home,” with a crying face emoji.

RELATED: Jessica Simpson Jokes ‘Not Everyone’s All Smiles’ Alongside Cute New Family Photo

A friend of Simpson tells PEOPLE that she is “doing great” after celebrating Johnson‘s 40th birthday this past Sunday “with close friends and family.”

Jessica Simpson/Instagram
Jessica Simpson/Instagram

“She’s working hard and working out and eating healthy and trying to get back in her best shape and excited for what’s ahead,” the source says of Simpson, whose upcoming memoir is set to be released on Feb. 4.

“She’s trying to get back to her healthiest place,” the insider continues. “And she just wanted to get to a place where she feels her healthiest. She’s not focused on the number, but on feeling her best self.”