As someone who grew up with Misophonia, I remember childhood being very challenging because at that young of an age its hard to understand what is going on and why you’re feeling this way which tends to lead to more anger. I remember at school the kids would eat goldfish and it would drive me crazy! One day, I couldn’t take it anymore so I asked my teacher if I could move seats. It helped me stay focused being on the edge of the room and away from the loud eaters. As a parent, I would make an attempt at speaking to her teachers and asking if she can move seats if things get worse for her because it does make a difference.
Coping at that age can also be difficult but there are things you can do. Sound machines can be placed in multiple places around the house and provide sound therapy and comfort for those with Misophonia. It is important that you make attempts at making sure she isn’t frequently exposed to her trigger sounds, especially in her home environment. We want her to have places where she can feel safe and comfortable and home should be one of those places.
As for family meals, try the sound machines in the kitchen and see if that may ease her a bit. If nothing seems to be working, I suggest finding another activity for family time such as going for a walk together after dinner or something like that.
I hope this helps!