help please

so my goddaughter has been complaining for the longest they it hurts when I wipe her down there after she uses the potty her parents assume that she knows how to wipe herself properly because shes potty trained now I told them they need to start wiping her with baby wipes boy toilet paper and stop letting her wipe herself and they don't listen I try to wipe her the best I can without hurting her but even the littlest touch seems to hurt her I found a bunch of toilet tissue build up down there on her when I took her a bath and it pisses me off what do I do she looks so irritated down there and I'm sick and tired of her parents doing this to her she's only two