That is incorrect info. Tammy's family was not even aware she was exhumed until they heard it on the news. They had nothing to do with her exhumation. The exhumation came after AZ law enforcement contacted the Fremont County Sheriff's office. It was AZ's investigation into the death of Charles Vallow and the attempted murder of Brandon B that set the ball rolling to get Tammy exhumed. That call from AZ LE came just days after Tammy's death. Please read and/or watch the sheriff's interview from January:
Sheriff details what happened when deputies responded to Tammy Daybell's death as Lori Daybell's son makes a passionate plea | East Idaho News
Trying to string things together a bit. In the 12/25/19 Gray Hughes video (43:45 min mark), the family member says "FBI has all this now. That investigator in Chandler did too and did nothing. Brandon is the reason this all started with the FBI. His investigator called FBI and then Chanlder (PD) got involved. Chandler wasn't going to get involved but because of what happened to Brandon, Chandler was forced to."
Then from the Sheriff Len Humphries interview by East Idaho News talking about Tammy's death, "Uh, a few days later (after Tammy's death) we started getting information out of AZ that we ought to maybe take a closer look at this. As a result of that, we got a court order in Dec and had Tammy's body exhumed and an autopsy was performed."
From Nate's interview with Gray Hughes on 3/1/19. (58:09 min mark) Nate says they get the daily police log every day, pages and pages with usually mundane things like a dog on the lose. "In October, before all this happened, mid-October, on the police log was listed something along the lines of 'need assistance from Gilbert PD in reference to two homicides, cell phone ping.' Well, we called the Sheriff's office and asked about this and they said the two homicides thing was a typo but yes, we're looking into it. Now I'm thinking that now looking back, they probably pinged Lori's phone and it was in reference to Charles' death maybe and Tammy died around that time, I'm not sure. (Note by me: What's not clear is whether the Nate's police log came from Fremont County or Madison County.) There was something there we put in the back of our minds. And then we find out that this beloved school librarian dies and they cancel school and everything ... then I get a text the beginning of Dec from someone who lives in the neighborhood and says you might want to look into that school librarian who died, Tammy Daybell, apparently there's more to the story. Call the Sheriff, get a vague response, then the story breaks."
Charles sent an email to Adam on 6/29/19 he says, "I asked her to explain it and she started blaming you, Brandon and me for perpetuating a scheme against her." And "Brandon and I are victims of her craziness."
Melani left Brandon and her kids behind and asked for a divorce in June. He said it came as a shock. The email would suggest that he was trying to help Charles and it would make sense that his involvement was at least in part, the catalyst for Melani leaving.
So, a lot of things are happening in June. Charles moves the family back to Chandler, AZ and rents a home. Charles, Brandon and Adam are accused by Lori as scheming against her, a common theme. Melani leaves Brandon and her children and asks for a divorce. Then on 6/28 Charles finds an email account Lori made in his name along with a letter from him to Chad. 6/29 Charles forwards the letter to Adam. Charles says he's going to contact Tammy.
Then in July, Brandon files for divorce on 7/8 and Charles is shot on 7/11. In October, Brandon is shot at on 10/2 and Tammy dies on 10/19.
Not sure of the point of this other than to set a mini timeline in my head of what may have set a series of killings in motion. I had always assumed that Brandon hired the PI after he was shot at but now I'm wondering if he was already on the case, possibly after Charles was shot? It also makes sense that the PI contacting the FBI would be the reason things kicked into high gear. The PI would be the hub of info tying everything together from multiple jurisdictions.
Not sure why I posted this as a reply to your comments. I had a reason when I started typing but by the time I finished, I had forgotten what it was.

MOO
Sheriff details what happened when deputies responded to Tammy Daybell's death as Lori Daybell's son makes a passionate plea | East Idaho News