In cases like this (and others) doctors and lactation consultants will recommend regular pumping sessions, or even pumping after feedings, to ramp up production. (romper.com)
It can take a month or more of regular pumping to trigger milk production (start slow but build up to eight to ten times a day). (babycenter.com)
With regular pumping or breastfeeding you should expect to see your milk come in anywhere in the range of 3 - 8 days postpartum, even after a c - section. (pumpables.co)