Absolutely, Clothes from Forever 21 will fit her. I am also 11 and their clothes fit me perfect and I'm a little bit taller than her. But she can always try shopping at stores like Papaya, Hollister , Tilly's , Wet Seal, Pacsun, and maybe Macy's and Jcpenny's in the teens sections. All these stores have really cute clothes for girls this age and it's affordable. But she will probably be an x-small or a small. Hope I helped. (:
