[user104658]

You can safely breastfeed on antidepressants so I'm not sure why she would have had to come off of them, but anyway, if she was indeed schizophrenic, this sounds a lot like a psychotic episode which would have been triggered by being off of antipsychotics (she may have had to come off them in pregnancy) or even just because of the surge of hormones that follows giving birth, which can render these medications ineffective even if they're not stopped. Dosages and varieties of these drugs are a fine balancing act and that hormonal change means a completely different balance needs to be found.

If she was diagnosed schizophrenic then I feel that psychological issues post birth, drugs or no drugs, we're all but inevitable and as such, someone somewhere (doctors, other hospital staff, even her family) have made a massive oversight by not ensuring that someone was with her at all times after the birth.