The pair are already partners in women's fashion collection The Row, and now Ashley's taking over the reigns of the project while her sister continues to act.
She tells VMAN magazine, "I've been transitioning from acting as a kid to doing something that I'm choosing for myself -- to be part of the fashion industry. That's what I want for my future. It has nothing to do with my past, nothing to do with anyone else's agenda. And I followed my heart the whole way.
"The Row is really something that I'm doing while my sister still wants to focus on acting. She's my partner in The Row, but she trusts me with the everyday. I mean, I see her like 10 times a day."
And Ashley, who is expanding the collection to include menswear in the fall, is urging critics not to dismiss her line as just another celebrity brand.
She adds, "The outside perception is very different because you do have celebrity brands, people like Jessica Simpson and Kimora Lee Simmons, and those are celebrity brands because they have their names on it."
(c) 2009 WORLD ENTERTAINMENT NEWS NETWORK LTD. All global rights reserved. No unauthorized copying or re-distributing permitted.