Taylor Momsen went from "Gossip Girl" to rock singer, and now she can add fashion model to her resume.

Momsen -- who is spending her summer on the Vans Warped Tour fronting her band, the Pretty Reckless -- stopped by Macy's Herald Square in New York yesterday (Aug. 3) to launch the new Material Girl clothing line, designed by Madonna and her daughter Lourdes "Lola" Leon.

Momsen told Billboard.com that signing on to represent Material Girl was an easy decision. "It's Madonna - she doesn't really do anything wrong, ever," the 17-year-old said in her dressing room, while a crowd of girls waited upstairs for her to perform. "So I had some faith there, and I saw the collection and it's really, really great.

"It's very much based on mixing and putting pieces together which I really like because that's what I do instead of pre-designed looks," added Momsen, who was styled by Lourdes for the Material Girl ad campaign. "She kind of reminded me of my little sister in a way. She was a very sweet girl, and [she has] great fashion sense." 

The Pretty Reckless: Summer Album Preview

A glance at the album art of the Pretty Reckless' upcoming debut album, "Light Me Up," suggests that Momsen has always been a style maven. The album, due Aug. 31 on Interscope, features a blonde toddler sporting a white T-shirt, leather jacket and a lighter. 

"The idea came from an old photo of me," says Momsen. "I was sitting on a baby motorcycle, with a leather jacket and sunglasses on when I was like 2 years old. The motif came from that."

Although she finished her stint on the CW's "Gossip Girl" after its third season, Momsen is not one to shy away from drama. The video for Pretty Reckless new single, "Miss Nothing," has the singer posing as Mary Magdalene - in nothing but form-fitting silver lingerie and spike heels -- in a "Last Supper"-inspired set.

"It seemed fitting for the song -- the song is about a lover dying," Momsen explained. "It's Jesus's last supper, and [Mary Magdalene] can't live without him."

The Pretty Reckless have tour dates lined up through Aug. 22, and Momsen has also been tapped as the face of John Galiano's perfume, set to launch this fall.