Thanks a lot David,
I think I couldn't get enough power to factory reset, as it seems in this situation, it will start, try to update it's files and will not trigger the charge so it will crash again on low power.
To successfully kickstart the kobo in this state where to battery is empty, I believe it needs a proper image so it can boot on low power, and then start charging.
My daughter's Kobo is now fully working, thanks for your image. Even if this devices are now 10 years old, finding help for it has been the highlight of my day
