Talk to Gynecologist on Gestational Diabetes

Hi this is behalf of one of my friend. she is 7 months pregnant and have gestational diabetes. Dr recommended her insulin 12 points 3 times a day, eating as per diabetes chart. walking half an hour after every meal. still sugar level is not dropping from last one month. diabetes is not controlled by any way. thats what she told me. is this normal ? what should she do? she has changed 3 doctors , still same