Praise be to Allah.
There is no basis for this hadeeth and it is not mentioned in the well-known books of hadeeth. Rather it was mentioned by al-Shaykh ‘Abd al-Rahman al-Safoori (d. 894 AH) in his book Nuzhat al-Majalis wa Muntakhab al-Nafais (p. 240), where he said:
It was narrated from the Prophet (peace and blessings of Allah be upon him): “If a woman does ghusl following her menses and prays two rak‘ahs in which she recites al-Fatihah and Surah al-Ikhlas three times in each rak‘ah, she will be forgiven every sin she committed, minor or major, and no sin will be recorded for her until her next period, and she will be given the reward of sixty martyrs, a city will be built for her in Paradise, she will be given light for every hair on her head, and if she dies before her next menses she will die as a martyr.” End quote.
The fact that this is the only book that mentions this hadeeth is sufficient to prove that it is false and fabricated, because it is a book that is filled with false reports. Al-Shaykh Muhammad Rasheed Rida said:
We cannot rely on the hadeeths with which books of exhortation, heart-softening reports and tasawwuf (Sufism) are filled, without examining their origins and degrees of authenticity. This ruling does not apply only to books whose authors are not known for having advanced knowledge (of hadeeth), such as the book Nuzhat al-Majalis, which is filled with fabricated hadeeths and other reports; rather even the books of some leading scholars, such as al-Ihya, are not free of many fabricated reports. End quote.
Majallat al-Manar, 3/545
And Allah knows best.