This hadeeth comes under the following chapter: PERMISSIBILIY OF COMPLETING THE (MISSED) FASTS OF RAMADAN BEFORE THE COMMENCEMENT OF THE COMING RAMADAN
'A'isha reported: If one amongst us had to break fasts (of Ramadan due to natural reasons, i. e. menses) during the life of the Messenger of Allaah (sallAllaahu alayhi wa sallam) she could not find it possible to complete them so long she had been in the presence of Allaah's Messenger (sallAllaahu alayhi wa sallam) till Sha'ban commenced.