Jessica Simpson climbing a bookshelf as a sexy librarian while flaunting her 100-pound weight loss proved just the ticket for fans today. The 40-year-old singer and actress was this weekend flexing her designer muscles for her Jessica Simpson Style brand – turning $1 billion in 2015 sales, the best-selling clothing label is still going strong. A snap landing on the brand's Instagram on Saturday showed off its CEO and the stylish merch, with fans absolutely loving it. Check it out below.