Celebrity Cameron Diaz Congratulates Sister-in-Law Nicole Richie on Her Collection with the Sweetest Post By Olivia Bahou Olivia Bahou Facebook Olivia Solomon is a New York-based writer and editor who covers all things fashion, lifestyle, celebrity, and pop culture. She was previously the Assistant Digital Editor for InStyle, and her work has appeared in many national publications. InStyle's editorial guidelines Updated on June 7, 2016 @ 02:45PM Pin Share Tweet Email Photo: Donato Sardella/Getty This famous family just keeps getting sweeter! Nicole Richie's newest collection launch became a family affair last week when hubby Joel Madden, his brother Benji, and his bride Cameron Diaz showed up to support her new line. But the love affair isn't over yet: Diaz just posted the sweetest message to her sister-in-law on Instagram. In the photo, the famous pals are embracing at the party celebrating Richie's House of Harlow 1960 collection with Revolve. "We're sisters because of our misters and I am SO impressed by and proud of how talented she is," the actress captioned the post. "Her capsule collection at Revolve is a wonderful reflection of her spirit and her style; sexy and chic, playful and grounded, feminine with a hint of masculine, retro yet contemporary. Congrats," she wrote. Richie told InStyle that the L.A.-inspired collection, which launched June 2 on revolve.com, is inspired by her stylish friend group, herself included. "What do I see my friends wearing? What can we pair with other pieces that already exist in our closet? What is the summer vibe?" she asked herself when creating the line. Nicole Richie's House of Harlow 1960 x Revolve Collection Is What Summer Dreams Are Made Of Shop the stunning pieces now on revolve.com.