What is the ruling on fasting make-up days when there is doubt about their validity, given the presence of a husband who prevents fasting, and is charity obligatory for the days in question?

If there is doubt about the validity of the fasting of the days being made up, the original presumption is that it is valid, and there is no need to make them up again. However, if the doubt is about the principle of making up some missed days, then she should assume the lesser number and make up what will clear her conscience. The husband has the right to prevent his wife from voluntary fasting, but he does not have the right to prevent her from making up missed fasts if their time becomes limited. Delaying making up missed fasts due to prevention does not excuse her and necessitates expiation for the delay, unless it is due to coercion.