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 ....) .