@Remus2
It's not likely anything can be done at this time, but it at least gives her another lead.
It's almost certain nothing could be don at this point. It's not like there would be any way to prove at this point that that particular packet of peanuts was contaminated with tree nut oils.
It's been known for a long time that peanut/tree nut oils can trigger allergic reactions.
Fortunately generally, skin contact is not enough to trigger a lethal reaction with food allergies, that takes ingestion. However, if a person with a peanut allergy touches a surface contaminated with peanut oil and then touches their lips, that can get the oil in their mouth and result in a potentially lethal allergic reaction.
What I'm having a hard time understanding is the general lack of knowledge on the subject. One would think something like this would be general knowledge?
General lack of knowledge on this doesn't surprise me. What does surprise me is that more people with peanut and tree nut allergies aren't more aware of this issue.
I don't recall where I first read about this issue, but from what I do recall, it took a number of deaths, mostly people with peanut allergies eating packaged tree nuts before the cross contamination in processing was figured out.
In hind sight the problem seems obvious. There are no major national brands that sell either peanuts or tree nuts that don't sell both.
The equipment used for preparing, roasting and packaging nuts is more or less the same no matter what kind of nut you are dealing with. So it's efficient to share facilities, equipment and workers between the processing of different kinds of nuts, including peanuts.
What may have been less well known before the advent of the "may contain..." warnings on peanut and tree nut packages is how little peanut oil or tree nut oil it actually takes to trigger an allergic reaction.