Asalamalikum. My wife before our marriage had made an niyath to keep nafl fast on monday and thursday after our nikah for the rest of her life. But due to some reasons she is not able to keep it regularly. Hence she skips it sometimes. I like to know is there is any alternative for the niyath she has made as per Islamic shariah. Kindly reply at the earliest because since missing of fast makes both of us feel guilty and we are not able to overcome that.