The back-to-school teen shopping scene looks a bit different at Westfield Montgomery mall this year. Windsor, a new addition in the Old Navy wing, is drawing high school and college girls with its moderately priced assortment of everyday outfits and formal dresses. Sneaker store KicksUSA has changed hands and changed its name to Snipes. The juniors department at Macy’s has been promoted from a hidden corner on the lower level to a prominent spot on the second floor. But the future is looking rocky for Forever 21, which once dominated the teen scene and now appears to be on the verge of Chapter 11. Forever 21 is practically an anchor at Westfield Montgomery, where it has a massive two-level storefront in what used to be the Sears wing.