I'm sorry for your loss. You and your sister are her heirs and have the right to her property once any creditors are paid. If you have a sibling that passed and left children, those children are heirs too.
You will need to go through the probate process for an intestate (left no Will) estate. This will provide notice to creditors and appoint you or your sister as the executor of the estate. The executor has the legal authority to sell and distribute estate assets. Nolo.com has some good information about the probate process, as does your state probate website. Good luck.
Answered on Feb 21st, 2017 at 4:34 AM