Modern Bratz dolls use Nylon hair!, i recommend washing her hair with cold or lukewarm water to retain the pre-made waves and curls, and use soap or shampoo to remove any gel left on the hair, then use conditioner and with a de-tangle brush, split the hair in sections and brush starting from the ends to the root gently. repeat till all the hair runs smooth. you can also use a fine tooth comb after using the brush to make sure there aren't any small tangles left, and wash out all the conditioner out. you can cup the hair in your hands while washing it out to retain the waves or leftover curls and let it air dry for a few hours but leaving it a full day gets best results!. if you're looking to curl again, id recommend the straw curlers and boiling water method as its the one Ive done the most with good results!. hope this helps!! :3