What should be done when fasting six days of Shawwal before making up the obligatory missed fasts and Ramadan is upon us before completing the make-up fasts, and is it permissible to offer money instead of food as expiation for making up missed fasts?

The sister who asked the question should have started by observing the obligatory make-up fast (Qada') before observing the supererogatory fast (Nawafil), if her breaking of the fast was due to a valid excuse. However, if it was without a valid excuse, then the make-up fast is obligatory immediately, and it is not permissible to delay it.