Guests included Stella McCartney, Ellie Goulding, Stephen Jones, Jacquetta Wheeler and Arizona Muse.
She has created 13-piece range that includes leggings, sports bras, a jacket, a hoodie, sweatshirts, a crop top, a jumpsuit and a yoga mat in pastel pink and floral patterns.
The model, who has designed a capsule line of jackets for Blazé Milano, plans to launch her own sustainable collection of party dresses.
The project will bring together designers and artisans from the 52 countries of the Commonwealth.
The book will launch in September and features Arizona Muse on the cover.
The retailer recently hosted launch parties to mark the collaboration in Los Angeles, San Francisco, Paris and New York.
Guests including Sir Phillip Green, Chloe Green, Julien Macdonald, Natalie Imbruglia, Jodie Kidd and Arizona Muse attended the Cash and Rocket gala.