what makes blood sugar drop
Usually a blood sugar in a normally healthy person will drop when they are not eating properly or sufficiently. If these are the times her sugar level drops then i would recommend she has some fruit such as a banana or peach to just raise the levels a little. The other cause is of cause producing too much insulin making the blood sugar drop dramatically.
Blood sugar levels that drop below normal are considered hypoglycemic, and can be caused by skipping meals, leaving too much time between meals, not eating enough, incorrect medication use (especially insulin), vomiting, diarrhea, vigorous exercise or drinking too much alcohol.