Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- Having more than one sexual intercourse in a single day has nothing to do with the woman’s duty of washing her hair during ghusl because this point is well established through the Shari`ah proofs.
2- The woman who has braids is NOT obliged to untie them when performing ghusl.
Sheikh Faysal Mawlawi, the late deputy chairman of the European Council for Fatwa and Research, states:
There is a unanimous agreement among Muslim scholars that washing the hair is obligatory for both men and women when performing ghusl.
The majority of Muslim scholars state that the woman who has braids is NOT obliged to untie them when performing ghusl.
Thus, what is to be done is washing the hair till the water reaches the scalp, and it is not sufficient to wipe over the hair without washing it thoroughly unless there is a clear sign that washing the hair will cause physical harm for the woman.
A reliable physician determines such case, and this gives a woman an excuse to wipe over the hair, without washing.
Rather, she can pour water over them till water reaches the roots of the hair and the scalp. The Prophet (peace and blessings be upon him) is reported to have addressed Umm Salamah (may Allah be pleased with her) saying,
“It is sufficient to pour water over your head three times and then pour it over your whole body three times, and with that your ghusl is completed.”
Allah Almighty knows best.