In my experiance, the dolls' hair is quite good a retaining it's original volume through lots of brushing and styling. Just make sure that you use a wire wig brush (like the one AG sells) to brush out her hair, and don't let her use any of your hair things either. The oils on human hairbrushes and hair accessories are VERY damaging to dolly hair. It also helps if you liberally spritz her hair with water before brushing and styling. ^_~

Also, if she does lose a bit of that pretty body wave, it's fairly easy to restore. =) Just put the ends in curlers and pour hot water over them, and those curly ends should pop right back into place. I hope that helps!