Something that might help is just being there to remind her that her emotions/self/life and all that deserve her attention as well. She’ll realistically keep trying to take their problems on herself but at least there will be another voice in her head telling her she matters too/ is her own person. Literally just talk to her about her day, if she shows interest in something encourage that and maybe gift her something small to help her progress.
I can pick out other peoples emotions with relative ease, but when it comes to my own I need to remind myself to pay attention by keeping a journal. I’ll bet I still would have issues if I had somebody like that, but they wouldn’t be as bad.