Peanut Allergy + Cast Iron Pan?

I'm having a guest over who is allergic to peanuts, and I sometimes use peanut oil to coat my cast iron skillet after use. It's been sitting on a hook on the wall for at least three weeks since the last time I used it and scrubbed it with kosher salt and then coated with a light amount of peanut oil - it was originally seasoned with salt pork fat.

Is the peanut oil going to cause a problem for this person? She tells me she is only slightly allergic but I know allergic people do not always have a mild reaction. If there is any chance that the allergens in peanut oil could still be on the pan, I can just use my calphalon instead.