Must a mother make up for the entire month of Ramadan that she missed due to childbirth if she is unsure about having made it up after twenty years?

Since the mother missed some days of Ramadan (definition), she must make up for the days she is unsure about having fasted, because the default is not having fasted. She was required to make up these days before the next Ramadan. Since she did not do so, in addition to making up the fasts, she must pay an expiation for delaying, unless the delay was due to a continuous excuse or ignorance of the ruling, in which case no fidyah (definition) is required from her.