Is it permissible to marry a Christian woman who declared her conversion to Islam years ago, but does not pray or fast?

It is not permissible to marry a woman who does not adhere to the rituals of Islam, such as prayer and fasting. Testifying to God's oneness and the Prophet's messengership necessitates action. This is indicated by the hadith (definition): "I have been commanded to fight the people until they testify that there is no god but Allah and that Muhammad is the Messenger of Allah, establish prayer, and pay zakat (definition). If they do that, their blood and their wealth will be protected from me, except by the right of Islam, and their reckoning is with Allah." It is incumbent to teach and guide this woman concerning the matters of her religion so that she may act upon them, for her turning away from action may be due to ignorance or heedlessness, not to rejection.