3 older sisters involved . I’m the youngest. And then there is the younger ,greedy widow.
If they have "filed paperwork" then it sound like a probate. Go to the courthouse and ask where the probate records are filed. Ask to see the file. The will should be attached to the Petition for Probate. Pay 50 cents per page and get a copy of the will.
Go look up the documents.
Go to the Probate Court for the county where he lived and look him up. If there is a Will then it was filed there and you can see it. If not, then you will find out if the family has started other proceedings. If there is no Will, then you are entitled to a share of the estate.
If someone has opened a probate you can get a copy of the will from the court. It is public record. If not, you can open probate yourself and that will smoke out the will. You should hire a probate attorney to help you.