A Muslim preacher claims women are too 'sensitive and delicate' to remember things properly because they can't handle stress and pressure.

The niqab-wearing former Christian, Um Jamaal ud-Din, told her 27,000 Facebook followers why Islamic law regarded a woman's testimony as being worth half that of a man.

The hardline, female Muslim teacher from western Sydney, previously known as Mouna Parkin, claimed women were unreliable witnesses.

Muslim preacher Umm Jamaal ud-Din (pictured) claims women are too 'sensitive and delicate' to remember things properly because they can't handle stress and pressure

The Sunni religious instructor cited a verse in the Hadith, chronicling the actions of the Prophet Mohammad, which described women as being 'deficient in reasoning'.

'Due to a woman being more sensitive and delicate in her nature, her ability to accurately recall information may be affected in situations where she's required to bear witness for cases involving conflicting parties, since such situations usually involve fairly high levels of stress and pressure,' she said on Friday.

The Quran, in verse 2:282, states that a woman's word is worth half that of a man's in a legal court.

'If there are not two men, then a man and two women from those whom you accept as witnesses - so that if one of the women errs, then the other can remind her,' it says.

Former Christian Um Jamaal ud-Din (pictured) told her 27,000 Facebook followers why Islamic law regarded a woman's testimony as being worth half that of a man

Umm Jamaal ud-Din, a female fundamentalist Sunni preacher, said she wasn't arguing that women had an impaired intelligence or memory, when referring to the Hadith.

'The deficiency in reasoning is in reference ... to do with a woman's accuracy,' she said later in a Facebook comment clarifying her position.

In her initial social media post, she claimed menstruating women were unable to fast or pray and needed to make up her 'deficiency' by doing 'righteous deeds'.

The Muslim teacher, previously described by the ABC as an 'Islamic scholar', has previously told her followers it was a sin for women to pluck their eyebrows and that Valentine's Day was immoral because it originated as a Christian festival.

In October, she slammed Muslim women for wearing rainbow hijabs as a 'sexualised' fashion statement.

The hardline, female Muslim teacher from western Sydney, previously known as Mouna Parkin, claimed women were unreliable witnesses