When baby is in distress (e.g. Mom has high blood pressure and baby isn't getting enough blood through the placenta) you can roll mom on her side. This relieves the compression of the giant baby-filled uterus on blood vessels (vena cava) and improves mom's circulation, thereby improving baby's circulation.  She wasn't able to do it herself because she had an epidural and because she's really fat. Not to mention that if she weren't fat, she might not have not had BP issues and the fetus might have not been distressed in the first place.