Answer by taking a quote from the following article:

Gwen Renee Stefani (; born October 3, 1969) is an American singer, songwriter, fashion designer, and actress. She is a co-founder and the lead vocalist of the band No Doubt that experienced major success after their breakthrough studio album Tragic Kingdom (1995) along with various successful singles, including "Just a Girl"

Stefani made most of the clothing that she wore on stage with No Doubt, resulting in increasingly eclectic combinations. Stylist Andrea Lieberman introduced her to haute couture clothing, which led to Stefani launching a fashion line named L.A.M.B. in 2004. The line takes influence from a variety of fashions, including Guatemalan, Japanese, and Jamaican styles. The line achieved popularity among celebrities and is worn by stars such as Teri Hatcher, Nicole Kidman, and Stefani herself. In June 2005, she expanded her collection with the less expensive Harajuku Lovers line, which she referred to as "a glorified merchandise line", with varied products including a camera, mobile phone charms, and undergarments. In late 2006, Stefani released a limited edition line of dolls called "Love. Angel. Music. Baby. Fashion dolls". The dolls are inspired by the various fashion that Stefani and the Harajuku Girls wore while touring for the album.  In late summer 2007, Stefani launched a perfume, L, as a part of her L.A.M.B. collection of clothing and accessories. The perfume has high notes of sweet pea and rose. In September 2008, Stefani released a fragrance line as a part of her Harajuku Lovers product line. There are five different fragrances based on the four Harajuku Girls and Stefani herself called Love, Lil' Angel, Music, Baby and G (Gwen). As of January 2011, Stefani has become the spokesperson for L'Oreal Paris. In 2016, Urban Decay released a limited edition cosmetic collection in collaboration with Stefani.  In 2014, Stefani announced the production of an animated series about her and the Harajuku Girls. Along with Vision Animation and Moody Street Kids, Stefani has helped create the show which features her, Love, Angel, Music, and Baby as the band, HJ5, who fight evil whilst trying to pursue their music career. Mattel have signed on as the global toy licensee and the series itself, Kuu Kuu Harajuku will be distributed worldwide by DHX Media.

has that fashion line been successful?
The line achieved popularity among celebrities