Jessica and Ashlee Simpson launched their girls' clothing line this week.

The sisters - along with Jessica's fiance Eric Johnson and Ashlee's three-year-old son Bronx - mingled with the young guests at Dylan's Candy Bar as the T-shirts, shoes and jeans went on sale for the first time. Proceeds from the sale of a specially-designed T-shirt will go to Baby Buggy, a charity founded by Jessica Seinfeld, while there are plans for an online design contest for a t-shirt to be included in the forthcoming back-to-school collection.

"It's a combination of both of our styles. Ashlee is very rock 'n' roll, and I'm very American," pregnant Jessica said, describing the new range, which is released through the Jessica Simpson label.

Jessica also revealed she has signed a deal for a maternity line and will also design girls' footwear. She also admitted she may branch out further if she discovers she is expecting a son: "Boys' clothing is a possibility." As well as awaiting the birth of her baby, Jessica is currently working on her spring 2013 women's collection, which she joked is so far out "my baby will be one."