Triple feeding late premature baby

Looking for some advice or (hopefully) some success stories from parents who are or were in a similar situation. My daughter was born at 35 weeks and is now six weeks old, and I'm still in triple feeding hell. For those who had similarly aged newborns and also had to triple feed, when did they "get" breastfeeding? She latches ok and will drink off and on for awhile, but I just don't think she's transferring well yet. We're still topping up between 40 - 80 mls after each feed for her to be satiated.