I remember being on the receiving end of this sort of thing. It's a vicious circle because the criticism beings to sound like a statement, it begins to define you, and then you think 'well, I'm so sloppy that I'm a lost cause - no point trying to be smart because I never succeed'.
Please do try to bite your tongue. The criticism really doesn't help, and it will make your dd distrust your judgement of her, and her own judgement of herself - believe me, I've been there.
Try finding things to praise about her, genuinely praiseworthy things, no matter how small. She'll see through empty praise. If she's sitting next to you, for example, you might just lift a lock of her hair, sift it gently through your fingers (once) and comment 'what nice hair you have' and that's all^. No 'I wish you would comb it more often', or 'Why don't you make this sort of effort all the time'.
She's probably having issues with her appearance and presentation herself, and struggling with them inside, and harsh criticism won't help her get through it. Or there may be reasons that you are not aware of which may be the root of her behaviour, anxieties that may seem trivial to you, but are overwhelming to her.
Please back off a little. I know you are a concerned mum and of course we all want to do our best for our children, gbut this is one time you must let go a little.