Is it necessary to make up the fast for a woman who broke her fast on the seventh day of her menstruation, thinking that she had not yet purified, even though she did not see any blood on that day?

A woman should not perform ghusl after menstruation unless she has verified that she is clean, because the default is that menstruation persists. A woman's fast is not valid before verifying purity, because the default is that menstruation persists. Her entering into the fast without being certain of purity means entering into an act of worship while doubting the condition for its validity, and this prevents its establishment.