Grandfather Died A Week After Marriage.

Location: Springerville, AZ

To preface im unofficially adopted, I gain or lose nothing from this. My two adoptive grandparents got married and 6 days later he passed away in his sleep, they have yet to identify the cause but we believe his heart gave out. The next day his son (who is not biologically related to the wife) drove down, neither family had known eachother there was some panic on the wife's side but ultimately it was decided to be hospitable, as this was a very distressing time espically for them and we wanted to air on the side of compassion. The day after the night he arrived he immediately began talks of legal what to do and who was getting what, requesting items, and various things. There is no will and and far as I know no trust has been found so far. The husband's oldest daughter is a millionaire. The wife, my grandmother was very upset by their intrusion and that they were trying to divy things up and take things away before he has even been buried. We are just getting a probate lawyer today but she has been ran out of the house and all of the husbands kids are there going through his stuff. The rich daughter has threatened that any legal action we take she will contest for years until my grandmother dies, and that she can either take his 600 social security each month or get absolutely nothing but shes not getting anything of his. She told me this directly last night. They are already accessing his accounts and going through his computers and phone today. The husband wanted her to have the house and his jeep. None of his kids supported the wedding and I have screenshots of what they have said with the husband greagly distressed over it. We called probate but while we wait what can we legally do. Im 20 years old and everyone is terrified of the power the rich daughter holds over us. She has threatened us multiple times and attempting to accuse my grandmother of everything under the sun.

Im worried having them in that house will lead to things going missing or anything in our favor being destroyed. What do we do?