...there's plenty of justification for taking her children away and no incentive to work toward reunification. After all, wouldn't the children be better off with another family? One much more mentally fit?

And then when each of those children starts to exhibit signs of distress ("symptoms"), again, if mental illness is the only frame to work with, then one doesn't have to look too hard at the allegedly more mentally fit family (or system). One only has to point back to the mother.

Oh holy hell