Yes, fat black girls can kick ass, no matter how young. They love beating up blonde girls, too (a hot woman even better). That cowgirl's karate wouldn't do her much good unless she can knock the fat chick out. But I've yet to see a skinny chick like that who has enough power to take out someone that fat. Heck, I don't even have enough strength to take that fat girl on. She'd wallop me.
Good thing the fight's not in the black girl's neighborhood or the cowgirl may not be getting up. This would be a pretty brutal fight with the black girl pummeling the blonde.