I was obese with both pregnancies. My first pregnancy I actually weighed 2 pounds less going in to delivery and left the hospital 15 pounds less than pre-pregnancy. I was very cautious about what I ate and continued to exercise and modified it as I progressed. I only gained 2 pounds with my second and again left the hospital weighing less than pre-pregnancy. I had 2 diffierent OBs in 2 different states and both were happy with how I did. I believe first pregnancy I weighed right about 200 pounds when I found out and with my second I was at about 220. No gestational diabetes, no complications with either.
I wish your friend well!