So I talked to mom, expressed my concerns, and she told me that they figure it is only a topical thing, so a skin reaction, not eating.
I told her that until we knew for sure she was putting her at serious risk, and me as well, and that I couldn't safely care for her until we knew for sure that she didn't have an allergy.
Anyways, she is going home to discuss with dad and will let me know what they are going to do.
I hate doing this. She is such a sweet little thing, too and a great family.