Menstruation and an expiatory fast

If a person owes days from Ramadaan and cannot remember how many they are

Ruling on one who has intercourse with his wife during the day in Ramadaan a number of times, not knowing the ruling

She reached the age of puberty but she did not fast Ramadaan

Ruling on one who breaks the fast because he is working in intense heat

She has not yet made up the fasts that she missed

She did not fast because of shyness

What should a person who did not fast do?