The Queen of Pop refused to take a back seat as the photoshoot for the children's clothing line got under way in Manhattan.

She made final adjustments to the clothing, hair and make-up and even took her own photos.

Momsen, who plays Jenny Humphrey in US TV series Gossip Girl, said Madonna wanted to add her own mark.

"Madonna totally came in and intervened and re-did everything and positioned everything into her own vibe," Momsen revealed.

"I think we had a very good working relationship. I think it went well."

The fashion collection - entitled Material Girl - was designed by Madonna and her daughter Lourdes, known as Lola.

Lola was also on hand on the shoot to help with styling.

"I worked with her to put the outfits together and she's a sweetheart," said Momsen.

"Madonna came a little bit later and she's totally awesome, a very down-to-earth girl with her success."

The Material Girl collection includes jeans, shoes, fingerless gloves, necklaces and other accessories.

Momsen, who is also lead singer in a band called The Pretty Reckless, said she is honoured to front the brand.

"I'm psyched to be the face of Material Girl. It's awesome." Momsen said.

"For one it's Madonna, so you know it's going to be cool. And it's been an awesome experience."