Answered by: Alimah Siddiqa al-Farsiyyah
Please answer my question urgently.
I have read on Islamweb that if a woman feels mathy, then her wudhu is not invalidated unless the mathy completely or even a bit comes out to the visible part of the labia minora. They said this appears to be the case because the jurists have stated that a woman only needs to wash the visible part of her vagina i.e. what is ordinarily visible whilst squatting during istinja, she is not obliged to put her hands in between her labia minora in order to cleanse.
If I release mathy and it has not spread onto the visible part of my labia minora, then do I not need to do istinja or istigmar (considering a women does not need to wash in between her labia minora anyway)?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
Madhi is a major impurity (najasatul ghalizah). If it doesn’t appear on your undergarment, then you are only required to squat and wash whatever is apparent with your palm, and you are not required to place your fingers inside of the labia minora. If it appears on your undergarment, it is forgiven only when it is an amount equivalent to a standard sized coin but when the amount exceeds this, then you must wash it off your garment.
Only Allah knows best
Written by Alimah Siddiqa al-Farsiyyah
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Al-Fatawa al-Hindiyyah 1/100-101, al-Maktabah al-Faisal
وَقَالَ عَامَّتُهُمْ: تَجْلِسُ الْمَرْأَةُ مُنْفَرِجَةً وَتَغْسِلُ مَا ظَهَرَ بِكَفِّهَا وَلَا تُدْخِلُ أُصْبُعَهَا. كَذَا فِي السِّرَاجِ الْوَهَّاجِ وَهُوَ الْمُخْتَارُ