Praise be to Allaah.  

When a woman has her period, she is spared the obligation of having to pray; indeed if a woman were to pray at that time she would be considered to be sinning and disobeying her Lord by doing so, and her prayers would not be accepted. 

Allaah has excused her from having to pray at the time of her period, and this is what is meant by the deficiency in her religious commitment as mentioned in the hadeeth of Abu Sa’eed al-Khudri who said, “The Messenger of Allaah (peace and blessings of Allaah be upon him) went out and said: ‘O women… I have not seen anyone more deficient in intelligence and religion than you. A cautious sensible man could be led astray by some of you.’ The women asked, ‘O Messenger of Allaah, what is deficient in our religion and intelligence?’ He said, ‘Is not the evidence of one woman equal to half the testimony of one man?’ They said, ‘Yes.’ He said, ‘This is the deficiency in her intelligence. Isn't it true that a woman can neither pray nor fast during her menses?’ The women said, ‘Yes.’ He said, ‘This is the deficiency in her religion.’”

(Narrated by al-Bukhaari, al-Hayd, 293; Muslim, al-Eemaan, 114). 

It was narrated that Mu’aadhah said: “I asked ‘Aa’ishah: ‘Why is it that a women who menstruates has to make up her fasts but not her prayers?’ She said, ‘That [menstruation] used to happen to us and we were commanded to make up our fasts but we were not commanded to make up our prayers.” (Narrated by al-Bukhaari, al-Hayd, 310; Muslim, al-Hayd, 508 – this version was narrated by him). 

Al-Nawawi said: “This ruling – i.e., that prayers should not be made up) is agreed upon by all the Muslims, that menstruating women and women who bleed following childbirth do not have to pray or fast at the times when prayers or fasts are due; they are unanimously agreed that they do not have to make up the prayers, and they are unanimously agreed that they do have to make up the fasts. The scholars said, the difference between them is that the prayers are many and are repeated, so it would be difficult to make them up, unlike the fasts.” 

(Sharh Muslim, 4/26) 

It was said that when a woman is menstruating, she is not obliged to perform the prayers at all, so it is not permissible for her to make up the prayers after she becomes pure (i.e., after her period ends). So how can someone else make up her prayers for her? Her husband does not need to make them up for her. This is apart from the fact that prayers cannot be made up for another person. ‘Abd-Allaah ibn ‘Abbaas (may Allaah be pleased with him) said: “No one should pray on behalf of another.” 

Every Muslim should keep away from innovating something in the religion for which Allaah has not granted permission. 

And Allaah knows best. 

May Allaah bless our Prophet Muhammad..