It typically takes an average of two months for a stone to be done up, and erected. 9 Aug was the start of the timeline, but the funeral wasn’t until 25 Aug. We are at the ninety-day point. It may be that the family wanted to use the headstone laying event as the next ‘arc’ to the storyline (I hate to compare it to TV episodes, but folks get manipulated by that).
Let’s see if they can remember where he’s buried.