What a horrible experience for her - she sounds very brave especially at 16.

The only thing that I can think that would make the mw say that would be to do with her iron levels after that sort of a blood loss (with that much blood, I would think she would have had a blood transfusion). If that is the case, then she probably should be on some sort of iron supplement.

Breastfeeding can add to decreased levels of iron in your body, but that just needs monitoring, it doesn't mean she can't.