There have been several small-scale studies that show that having a mother with hepatitis C does not increase a baby's risk of picking up the virus and becoming infected. It would be nice if the studies were larger but that's all we have for now. In general babies are protected from infection by breast milk, so even the very prudent Centers for Disease Control recommends that women who are carriers for hepatitis C can breastfeed.
There is concern though that if the mother has bleeding nipples the likelihood of transmission to the baby might increase, but there is also no evidence for this. However, it’s prudent to start breastfeeding properly so that you don't get sore or cracked nipples. My book, The Latch and Other Keys to Breastfeeding Success, and the website NBCI.ca can show you how to latch a baby on well and how to prevent sore nipples.