I learned from my c-nanny that it is important to know if your friend is having c-sect or natural delivery. Also if she is planning to breast feed or using formula. I'm just going to assume she is having natural and will be breast feeding.
First 2 weeks, eat naturally ie no super strong nutritional stuff. Start taking super strong nutritious soup from Day 20 to day 30. For best body absorption take 2-3 days of strong nutritional soup (Chinese herbs eg. Cordyceps), then next 2-3 days less strong nutritional soup (eg. abalone/conch/papaya soup). So, the body have a better chance to absorb the nutrients.
Papaya soup is well-known to increase milk production. However, a super strong ingredient which can be bought from chinese herbal shop, looks like Polo sweet but light (sorry, forgot the name!) can be added to the soup and it can increase the milk even quicker.
Strong nutritional soup - Korean Ginseng (Ko Lay Sum) soup or Cordycep soup.
Super strong nutritional soup - Velvet (Lok yung) soup. This is for blood circulation.
Less strong nutritional soup - Papaya and fish soup, turtle soup (Sui Yi), Chicken essence, Chicken soup, Lamb soup, Shark Cartilage soup, Fish maw soup, Lingzhi soup.