Jessica Simpson's eldest daughter has helped her conquer her lifelong fear of horses.

The singer/entrepreneur recruited her girls Maxwell and Birdie to join her as models for the latest collection in her namesake fashion empire, and her eight-year-old insisted on featuring her favourite horse in the photoshoot, even though she knew Jessica was not a fan of the animals.

However, Maxwell encouraged her mum to let go of her anxiety by leading her in a symbolic chant to cast her fears aside as they prepared to pose for the pictures.

"My oldest, Maxwell, teaches me every day to surrender...," Jessica told U.S. breakfast show Today.

"We were doing a Jessica Simpson Collection photoshoot, and she wanted one of the horses that she rides to be in the shoot.

"This is her way of like, 'I'm gonna make mum ride this horse.' She's like, 'Horses know that you're afraid, mum, (but) let's just stand at the mountain and scream over the mountain, 'I throw my fear over the mountain!'

The action made Jessica feel empowered and helped to ease her nerves over modelling with the horse.

"Then, I went back to the horse and Maxwell handed me the reins and gave me the lead. It was a beautiful moment," she smiled.

However, the sweet scenario didn't last long.

"I took the reins, and of course the horse emptied out like, four days' worth of pee!" the 40-year-old laughed.

The star shares Maxwell, two-year-old Birdie, and seven-year-old son Ace with her husband Eric Johnson.