Ahmad Ibn Abdi l-Wahhab An-Nuwairi writes:

وَادَّعَـتِ امْـرَأَةٌ الـنُّـبُـوَّةَ عَـلَـى عَـهْـدِ الْـمَـأْمُـونِ فَـأُحْـضِـرَتْ إِلَـيْـهِ فَـقَـالَ لَـهَـا: مَـنْ أَنْـتِ؟ قَـالَـتْ: أَنَـا فَـاطِـمَـةُ الـنَّـبِـيَّـةُ فَـقَـالَ لَـهَـا الْـمَـأْمُـونُ: أَتُـؤْمِـنِـيـنَ بِـمَـا جَـاءَ بِـهِ مُـحَـمَّـدٌ صَـلَّـى الـلَّـهُ عَـلَـيْـهِ وَسَـلَّـمَ؟ قَـالَـتْ: نَـعَـمْ كُـلُّ مَـا جَـاءَ بِـهِ فَـهُـوَ حَـقٌّ فَـقَـالَ الْـمَـأْمُـونُ: فَـقَـدْ قَـالَ مُـحَـمَّـدٌ صَـلَّـى الـلَّـهُ عَـلَـيْـهِ وَسَـلَّـمَ: لَا نَـبِـيَّ بَـعْـدِي قَـالَـتْ: صَـدَقَ عَـلَـيْـهِ الـصَّلَاةُ والـسَّـلَامُ فَـهَـلْ قَـالَ: لَا نَـبِـيَّـةَ بَـعْـدِي؟ فَـقَـالَ الْـمَـأْمُـونُ لِـمَـنْ حَـضَـرَهُ: أَمَّـا أَنَـا فَـقَـدِ انْـقَـطَـعْـتُ فَـمَـنْ كَـانَـتْ عِـنْـدَهُ حُـجَّـةٌ فَـلْـيَـأْتِ بِـهَـا وَضَـحِـكَ حَـتَّـى غَـطَّـى عَـلَـى وَجْـهِـهِ

,,In the time of Ma’mun, a woman claimed prophecy. So she was brought to him, whereupon he said to her: ﴾Who are you?﴿ She said: ﴾I am Fatimah, the Prophetess.﴿ Then Ma’mun said to her: ﴾Do you believe in what Muhammad (s.) brought?﴿ She said: ﴾Yes, everything he brought is true.﴿ So Ma’mun said to her: ﴾Muhammad (s.) has said: ,,There is no prophet after me.”﴿ She said: ﴾He has spoken the truth. Blessings and peace be upon him. But did he say: ,,There is no prophetess after me?”﴿ Then Ma’mun said to those, who were with him: ﴾As for me, I am finished. Now whoever has an argument, let him bring it.﴿ And he laughed until he covered his face.” [Nihayat-ul-Arab, Volume 4, page 17]

Comment:

An-Nuwairi is an Egyptian historian