He replied:

Her father has no right to manage her property for his own benefit. Indeed, if he does so, this impairs his fitness to act as her guardian, and he must be barred from exercising guardianship over her, including placing her under legal interdiction. If, however, he is fit to act as her guardian and manages her property solely for her benefit, not his own, his guardianship over her is conditional upon her continued financial imprudence. Once she develops sound financial judgment, her interdiction ends regardless of his wishes. If she produces evidence of her sound financial judgment, a ruling must be issued terminating his guardianship over her. She is entitled to require him to swear that he does not know her to possess sound financial judgment, if he seeks this without producing evidence. Allah knows best.

He was asked:

A woman claimed that she was under legal interdiction, although her husband had not known this. He then divorced her, and she released him from his financial obligation to her. She subsequently married another man, after which a claim was brought against the first husband for the dowry on the grounds that she was under legal interdiction. Is this claim to be accepted?

He—may Allah have mercy on him—replied:

The claim is not accepted merely on her assertion that she is under legal interdiction. Rather, if she conducts her affairs as a person of sound financial judgment would, then she possesses sound financial judgment and her sales are legally effective, even if she is under legal interdiction. If she produces evidence that she possesses sound financial judgment, her voluntary waiver is fully effective. Allah knows best.