I suppose there could be many reasons why a woman produces no milk at all, and it does happen. A friend of mine BF her first two babies and had her 3rd via induction 2wks early due to pre eclampsia and she produced no milk at all. Not sure if she still had colostrum - I am assuming she did, but I guess the stress of an early delivery (albiet only two weeks) just did something so her body didn't produce any. She went on to BF her 4th bub too with no worries though.

As for your MIL, maybe she doesn't mean she literally had no milk but jsut the assumption she didn't?