Suggest Treatment To Manage Blood Sugar Levels During Pregnancy

Hi..My wife is pregnant now and she is in 23rd week. She has type 2 diabetes and initial days of pregnancy she had metformin 500 mg twice per day..but currently she is taking insulin and her sugar level lies below 100 before breakfast and lies around 150 -165 for post breakfat , lunch and dinner..is this a good indicator or something not good ?