In a book I am reading person A asks person B about person C; person C used to be mad, and person A asks person B how C is doing now. Person B answers: "Plus folle du tout".
How can I know if this means "no longer crazy at all" or "even crazier"? I know that in speech the "ne" is often omitted when "plus" used in a negative sense (as in "no longer"), and moreover since "du tout" means "at all", and "at all" in English is usually accompanied by a negation, I am inclined to think this means "no longer crazy at all". But perhaps "du tout" in French is used differently than "at all" in English and this actually means something like "even crazier".
Does "Plus folle du tout" mean "no longer crazy at all" or something like "even crazier"?
Here's some context, although I would prefer not to rely on it too much (except for grammatical purposes). After person B describes how she went mad, they went on to say:
Le médecin disait: "Il faut la marier, il n'y a que ça qui peut la guérir... Ça lui doublerait les sangs…"
(I have no idea what he means by "doubling her blood" but I don't think it's relevant). Then later person A asks:
Et elle a eu les sangs doublés?
and person B answers:
Oui, monsieur, ça vous pouvez le dire ! Doublés, ce qui s'appelle doublés. Plus folle du tout.
I am aware of the fact that the context alone makes it a lot more likely she is no longer crazy at all - since person B confirms she "had her blood doubled" (whatever that means) - but I prefer not to rely on it too much because this might be ironic.