Re: One breast producing very little milk
The main way you know if your breastfed baby is eating enough is 1) does she have 6-8 wet diapers in 24 hours, and 2) is she gaining weight appropriately. If she's doing those, then she's getting enough to eat. Many mamas have fed twins with 2 boobs or one baby with one boob, so that in itself is not a cause for concern. Sometimes people are worried about lopsidedness, which is an aesthetic or comfort concern.
But some questions for you:
1) Is she eating any solids? cereal?
2) What makes you think she doesn't get much milk out of the left? How did you come to be feeding mostly from the right?
Nursing, pumping, cloth-diapering, babywearing, working professor mama with the awesomest SAHD ever.