It is not permissible for the menstruating Woman to fast
Question :
May the woman who is menstruating break her fast during Ramadhan and fast other days in place of the days that she broke her fast?
Answer:
The fast of the menstruating woman is not correct and it is not permissible for her to do so. So, if she gets her menstrual cycle, she breaks her fast and fasts other days in place of the days that she broke her fast after she becomes pure.
Source:
Fatawa Islamiyah, Vol. 3 Page 296