Rasulullah (sallallahu alayhi wasallam) said that fasting the Month of Ramadhaan and Six days during the month of Shawwaal is the equivalent of fasting the whole year.
These Six fasts begin from the 2nd Shawwaal (the Day after Eid), and may be kept all in a row, one after the other, or they may be spread over the month.
Salafis reject the validity of these Six Fasts of Shawwaal. Since Salafis are morons and astray, ignore their stupid talk.
Women who have missed fasts in Ramaadhaan and who lack the strength and stamina for keeping their Qadha plus the six days, should rather fulfil (make Qadha) of their Ramadhaan fasts. Insha-Allah, they will also gain the thawaab of the Six days.