I have a friend who just gave birth to Triplets but they are premature babies (only 7 mths when they are born).
How do we know if they are getting enough milk? Is there anywhere where we can find breastmilk donation if my friend really hasn't got enough milk supply?
As far as I know there are no milk banks in Hong Kong. And it would not be considered safe to get breast milk from other mothers without a full medical screening of the donating mother and pasteurization of the donated milk.
Are the babies able to breastfeed? If so then the ways to tell if they are getting enough milk are the same as for single babies. How to know your Health Full-term Breastfed Baby is Getting Enough Milk, http://www.lllhk.org/566-27HK-Chinese.pdf (page 2 is English)
If the babies are not able to actually breastfeed, or if they are only managing to feed in a weak way, then the mother needs to be encouraged to express or pump her milk. Generally hand expressing is more stimulating and generates more milk than pumping in the first few days while the mother has colostrum.
The mother needs to express/pump at least 8 times in 24 hours but 12 times would be better. Once the milk has increased I would recommend getting a hospital grade electric pump.