What should a husband do with his wife who is lazy about Fajr prayer in winter?

The husband should remind his wife of the obligation of prayer and the danger of neglecting it, seeking Allah's help, and utilizing all possible means of da'wah (invitation to Islam). He may also connect her with good company. If she persists in her negligence of the Fajr prayer, he should abandon her in bed. It is permissible to strike her with a non-injurious blow if he believes it will be effective, as a means of disciplining her for her shortcomings in fulfilling the rights of Allah.