I have heard (from a respected NYC breast surgeon) that milk will flow through
the area of least resistance, if there is a drain, it will flow there, if
there is an incision and the mother is not nursing, it will flow out the
incision, if the mother is nursing, milk will flow out of the nipple
preferentially.  Could the drain be removed and the mom return to full
breastfeeding?
Catherine Watson Genna, IBCLC