I have to handle my mother's affairs and I am unsure if I can use a small estate affidavit now and petition for administrator later.

My mother died intestate in Kansas. She died in a nursing home and had no estate to speak of- no car, no house, no insurance. Only some clothes, books, and small electronics. Her bank accounts were jointly owned with my brother and the bank has stated that he takes over ownership. Normally, I could use a small estate affidavit. However, she was a beneficiary of her brother's estate. He passed a few years ago and his estate has not been completed. They want to make any distributions to her estate, for which there will need to be a new account opened. I don't know when this will happen or how much it will be, but assume there will need to be an administrator. However, if I were to start probate and file to be administrator now, there is nothing to probate at the moment. How should I proceed?