R.H.
I have a niece in the same situation as your daughter. She is also 11 yrs old and a bit on the overweight side. My Mom, bought some clothes for her at BELK her in McKinney, they seemed to have some plus sizes for girls, and we noticed some blue jeans at KID to KID(resale shop)in the plus sizes as well. There is also a JUSTICE for girls in McKinney in the Eldorado Plaza, that might have something. Hope this helps.