What kinds of foods are you offering?
Russians (horsefield) should have a variety of leafy weeds and greens.
This is a care sheet that may be helpful, there is a section on diet towards the end, but I recommend reading the whole thing. https://tortoiseforum.org/threads/russian-tortoise-care-sheet.80698/
Feel free to ask anymore questions or have us explain something. If you have weeds growing in your yard we are happy to help ID them so you know if they are safe.
She only seems to want to eat kale and spinach and occasionally rocket. I have tried other supplements via the tortoise shop I purchased her from but I’ll keep on trying and thanks.