The pair have collaborated on a children's clothing and accessories range for US department store Macy's, and Madonna confesses 13-year-old Lourdes brought much of her own personal style to the collection, entitled Material Girl.
She revealed: 'I think this line is absolutely an extension of her taste.'
'We like to combine a plaid or a flannel with a lace or leather with lace or rhinestones. So we mix and match textures and fabrics and elements that are both masculine and feminine.'
The range, which includes clothes, handbags and jewellery, will range from $12 to $40.