Food intolerances can appear when the substance in question was somehowe connected to a UDIN, and saved as a warning trigger. The symptoms prompted by the intolerance reflect what kind of theme the UDIN had. Like, skin rash = contact/separation, breathing trouble = invasion of territory etc
Having said that, if your friend is fine with what she found out, good for her! She wouldn't have a motive for digging deeper. We usually get the clients that aren't yet happy with their situation.