I can't help/ advice you with this one, I'm sorry. But I know exactly what you mean. That thought crossed my mind a thousand times. But my fillings are on my front teeth...The worst of this is that dentists are not (well )familar with biocompatibility so try to explain something like this....
If she may do so, don't do them all at once. I don't know if you are familiar with Omar Amin? He says to do two at the same time and then wait two or three months for the other ones. Is she becomes in pain after removing them then here problems are definitly caused by her composites. She probably is going to have a hard time ahead and in advance I'm so sorry for that. Be strong for and with her.
My healthproblems ( and they were bad )are still ignored by health and dental care. They ignor everyrhing I say because my story sounds weird...And if the story is weird, the person must also be weird.