I think she must do a complete study
of possible causes
of hypoglycemia, there are some other endocrine deficiencies, certain disorders
of the adrenal glands and the pituitary gland that can result in a deficiency of key hormones that regulate glucose production. I would recommend her to do much more tests (when the glycemia is low) to find out (exclude) the causes (ex. of some tests: insulin , C peptide, cortisol, ethanol, Hemoglobin A1c ....) .