Hmm...Actually, now that I'm reading this and looking at some past chapters, I understand that they mean well, but they are also outright rejecting the only way she knows how to do things. It's obviously upsetting to her, even if the methods she's using are impractical and make her life worse, that's how she was taking care of herself. They're basically telling her that not only is she wrong, but that she can't care for herself at all. At least, I think that's how she is taking it.
Honestly, I don't think that she's bothered much by that. She's shown that she's more than willing and happy to learn how to do things from the others regardless of her previous experience with things.
The thing that I believe that continually bothers her is that everyone at Hyudor's castle is so nice to her that she wants to be able to do something to repay them for that. The problem however is that almost everyone there is highly capable and that there's very little assistance that she can offer. This problem magnifies as everyone still continues to be nice to her which spirals her into a series of self doubt and self loathing at being unable to repay the kindness.
That said, Hyudor and the others aren't being nice to her with repayment on the mind. They genuinely care for her and want to give a happy and loving enviroment, something she lacked. Now Hyudor and the others could sit down with her and have a talk about it, but I don't think it'd do much good (at least not by itself). If anything, I think one of them did talked to her about it (at least if I remember correctly).
The biggest hurdle however was that of her past experience as a hero for humanity. Her previous role as a Hero (at least when she was a hero for humanity) meant that she had a huge weight on her shoulder and that she had to meet the expectations that people had of her; and due to how dutiful she is, she couldn't just quit (since we saw that she still continued to be a hero despite how much suffering it caused her). The only way she could stop was if she defeated the demon lord (and thus fulfilled the expectations that were expected of her) or died in the line of duty (which was why she somewhat welcomed death at the first chapter since she would be relieved of duty and reunite with her parents). Also judging from her reaction to various things, she likely was rarely (if ever) praised for her actions as a hero, also she was probably barely supported and/or accomadated by people since she wasn't used to washing in a tub and had to make do in a freezing river.
Long story short, I don't think we'll move past this self doubt until a serious catalyst occurs, such as Rene and Hyudor running into some humans who knew her and abused her, and/or Hyudor willing to stand up to anyone in order to keep Rene safe including the demon lord.