Ashlee Simpson models for sister Jessica Simpson’s fall line

Ashlee Simpson is modeling for older sis Jessica Simpson’s fall fashion ad campaign.

Sporting blond locks, Ashlee Simpson, 28, reminds us of a youthful (ahem, thinner), pre-baby version of Jessica, 33, in the latest video. Watch it above.

Jessica, the former pop star, has found quite a bit of success in fashion with her department store-ready brand, even appearing as a mentor in NBC’s recently canceled “Fashion Star.”

PHOTOS: 50 most beautiful female celebrities

Ashlee is seen fluttering about in the playful video, posing, sitting on cars, walking through fields and getting all dolled up. The bohemian rancher rocks out in printed dresses, cozy sweaters and silky PJs. The print campaign was shot by photographer Ellen von Unwerth, and the music in the video sounds vaguely Simpson-esque.

There’s jewelry, handbags, clothing racks, scarves, watches, boots -- and a saloon! Sneak peek at the fall 2013 collection? Check.

The rocker chick is doing farm girl chic in the clips and a pregnant Jessica appears in the behind-the-scenes clips from the video.

“Jessica always wants me to be comfortable ,so it was an honor that she had me do this and it’s fun to work with my sister and family,” Ashlee told E!. “And if I say no or feel uncomfortable, she’s like, ‘Let her out of that outfit, she’s not going to wear that.’”

Ashlee seems to be taking on her sister’s spokeswoman duties as Jessica focuses on her new baby boy Ace, born June 30. Ashlee not only attended the official launch party for the campaign Tuesday, she actually hosted the event at Above Allen in New York City.

Jessica’s “a bit more girlie, and I kind of like to bring an edge to my looks. I do like to be in dresses, I just like to toughen it,” Ashlee told People at the event. “We were all having a good time, kicking dirt in pretty dresses. They did tell us to look for ticks! And I was like, ‘OK, I’m just going to roll in the dirt.’ ”

So one question remains: Is it fall yet?

ALSO:

Kristen Stewart gives paparazzo a tongue-lashing in L.A.

Amanda Seyfried tripped up by heels, fans before ‘Letterman’

Princess Diana: Mag details ‘secret romance’ with Pakistani doctor

Follow Ministry of Gossip @LATcelebs.