I recognise you from the adoption board.
You are brave posting in aibu! You've just adopted your fifth baby. You will be at your most stressed just now, and all the kids will be adjusting. You are allowed to be feeling wobbly, unreasonable, and need kid gloves. Fuck off everyone else judging OP, OP deserves a large gin and biscuits.
So, the grandparents are not willing to observe the rules you have put in place to help your vulnerable, traumatised children to feel secure, loved and happy, is that right? That is very difficult, and something non-adopters may not understand.
Are you worried missing these gifts will be seen as a rejection by your DD and other kids? The last thing adopted kids need is anything rejecting. I know you know that, OP, but others posting probably haven't thought about it.
I can well believe that traumatised kids with extreme fears of rejection, pretty typical for adopted kids, would cry for their grandma, and not understand why she's putting someone else before them. I can also understand that yelling is never acceptable in a household with traumised kids.
OP, fancy a chat over on adoption?