Question: My wife broke her fast in some days during Ramadan due to her childbirth. I keep advising her to make up for these days, and she usually expresses her willingness to do so. However, she does not fulfil her promise; she would observe the fast for a couple of days and then abandon it. What is the ruling on this?
Answer: If the case is as you have mentioned, your wife is obligated to make up for the days on which she broke her fast in Ramadaan due to her delivery. It is not permissible for her to delay making up for them until the next Ramadaan. If she does so with no excuse, she would be sinful and must repent to Allaah. Accordingly, she should start making up for them immediately and offer Kaffaarah (expiation) to compensate for her negligence, i.e., she should feed a needy person about one and half a kilo of rice or any other staple food of the country for each day… read more here.