What happens when there is a situation of a death of a sibling and there is no living will no named beneficiary and it is unknown where the mother is

Recently my sibling had passed, she had left no legal will and had not named a beneficiary or executor of the estate. The last known information of the mother was she was imprisoned somewhere in a different state but it is unknown if she is still living as I had tried to make contact with her and was unsuccessful. I took care of the funeral services, canceling car insurance, informing bill collectors of death and collected her car from the state police which is now in my possession with signed documents. Pretty much it was dumped on me to tie up all the loose ends. I have all the paperwork from her work that was given to me with the information of life insurance and 401k , if her mother is alive, is she still entitled to receive anything?