Is it permissible to combine the intention of fasting the six days of Shawwal with making up missed Ramadan fasts (due to menstruation) with a single intention?

It is not valid to fast the six days of Shawwal for someone who has make-up fasts from Ramadan, because they are linked to the completion of the entire Ramadan fast. Whoever fasts them before making up the missed days will not receive their reward, due to the Prophet's (peace be upon him) saying: "(Whoever fasts Ramadan, then follows it with six days from Shawwal, it is as if he has fasted the entire year)." And whoever has make-up fasts is not considered to have fasted Ramadan until he completes it.