hubbys grandma being shady

long story here but I'll try to sum it up.

it's been a rough week, we had a passing in the family and we're at the visitation the night before the funeral. I am 35 weeks pregnant and have been given an induction date due to gestational diabetes and our families are excited... except his grandma who is mad that his parents would rather be with us for the birth of their grandchild then go several states away for a highschool graduation party. Grandma makes a scene in the funeral parlor about why would they not be there for the graduation because it is "rude to not attend their neice's grad party" "she'll only graduate highschool once" even though they only see her when they come back (not to see family mind you but for their favorite football teams games) I personally don't like the woman anyway but I feel bad for my in-laws. they are very nice people (black sheep of the family unfortunately) and don't feel they should be guilted for wanting to be there for us and this will likely start a fight with the extended family because they act like I have a choice because you know baby girl and my health aren't that important (hint of sarcasm) makes me want to slap his grandma.