Is it permissible to delay the ghusl after menstruation from 9 AM until near Dhuhr, or is it obligatory to perform ghusl immediately?

If a woman's menstruation ends in the forenoon and she wishes to delay her ritual bath (ghusl) until the time of the Dhuhr prayer, there is no harm in that. This is because the ritual bath from menstruation, postpartum bleeding (nifas), or a state of ritual impurity (janabah) is an obligation that can be delayed, not one that must be performed immediately. It only becomes obligatory when one intends to perform prayer. This is supported by the Hadith of Abu Hurairah (may Allah be pleased with him), who met the Prophet (peace be upon him) while Abu Hurairah was in a state of janabah. Abu Hurairah delayed in order to perform ghusl, whereupon the Prophet (peace be upon him) said: "Indeed, a Muslim does not become impure." Ibn Hajar commented: "This indicates the permissibility of delaying the ghusl from the first moment it becomes obligatory." And in the Hadith of Aisha (may Allah be pleased with her), when she was asked about the Prophet's (peace be upon him) state of janabah, she said: "He would do all of that; sometimes he would perform ghusl and then sleep, and sometimes he would perform Wudu' and then sleep."