Inside Jessica Simpson's Stylish Ski Trip With Sister Ashlee -- See the Pics!

Jessica and Ashlee Simpson
Jamie McCarthy/Getty Images for Jessica Simpson Collection

Looking good, Simpson sisters!

Jessica Simpson is ringing in the New Year in style!

The 39-year-old fashionista has been spending some quality time with her family in Aspen, Colorado, taking to Instagram to document their fun-filled ski trip. 

Jessica, who just gave birth to daughter Birdie (baby No. 3 with husband Eric Johnson) in March, showed off her slimmed-down figure in one of the pics, proving that even snowsuits can be chic! The blonde beauty is also mom to daughter Maxwell, 7, and son Ace, 6, who joined her and Eric on the family getaway.

"Skiing with the kiddos today," Jessica wrote. "This is as far as I got..."

Jessica's sister, Ashlee Simpson, is also in Aspen, along with her kids -- Bronx, 11, and Jagger, 4 -- and husband Evan Ross. They looked oh-so-adorable while posing in matching red onesies, as the snow provided a perfect backdrop for their family pic on Christmas Day.

The view was even better on Monday, however, and Jessica captured it all on camera. The mother of three rocked an all-black snow ensemble, complete with a white fuzzy hat and ski goggles, while Ashlee sported a bright blue snowsuit and showed off her pretty pink locks.

"Ski lovers ??❤️?," Ashlee captioned a photo of her and Evan on the slopes. 

The Simpsons were also joined by Evan's family, including mom Diana Ross and sister Tracee Ellis Ross. See more cute snaps from the Aspen trip below:

Jessica revealed via social media in September that she lost 100 pounds following the birth of Birdie. ET spoke with her trainer, Harley Pasternak, who gave us some insight on how the mother of three shed the baby weight and is working to maintain her fit physique.

"She lost the weight because of everything she did when she wasn't in the gym. Of the 168 hours of the week, she's only working out around three of those," he explained, telling ET he had Jessica walk 12,000 steps a day. "After she gave birth, we kind of had to work up to that."

Hear more in the video below.