I wonder whether the OP's daughter was told that babies can survive on 1 ml of fluid an hour? When my premature grandaughters were in special care, they were fed by breast milk through a tube during the first few weeks, until they could suck. The 2 lb baby was being given 2.1/2 mls every 2 hours and it crept up over a few days to 5 mls every 2 hours, which seems a minute amount, but the nurses have a formula to calculate how many mls for the weight of the baby will put on weight.
After a month, a 10 ml syringe of breast milk was pushed down the tube into their tiny stomachs, following each attempt at feeding, until they were taking expressed milk from a bottle every 3 hours. By that time, the milk was donated - daughter ferrying up and down to hospital 3 times a day had put the kibosh on her attempts to keep her breast milk flowing, despite GP's help. They have thrived, though