She vowed to fast for a month, should she make up the days when she was menstruating?
Question

                I vowed to fast for a month. Do I have to make up the days when I was menstruating after I finish the vow?.
Praise be to Allah.If a woman vows to fast 
    for a month, then she should make up the days when she was menstruating, 
    just as she makes up the days when she menstruates during the month of 
    Ramadaan. 
See al-Mughni by 
    Ibn Qudaamah, 10/86. 
The Standing Committee 
    for Issuing Fatwas was asked this question and replied: 
You have to fast the 
    month which you vowed to fast, and if you break the fast during part of it 
    because of menstruation, then you have to make up the number of days of that 
    month when you did not fast. 
And Allaah is the Source 
    of strength. May Allaah send blessings and peace upon our Prophet Muhammad 
    and his family and companions. 
Fataawa al-Lajnah 
    al-Daa’imah, 23/336.