Just another thghout...If she is that sensitive to sals she is probably not tolerating additives and preservatives whihc have a very similar toxic effect as sals. They are just the synthetic version of food chemicals. So of the foods are frozen, they probably have preservatives in them.
Kai is very sensitive to preservatives and additives, actually it has been shown that most kids are affected in some way, even if its just restlessness and temporary hyperactivity.
As far as sals go I would be thinking what oil was the chips cooked in? And also the spices in the sausage rolls.
Unfortuntely we can only eat preservative free sausages and must ask the butcher to make them specially, then forkout to buy 5kg at a time!