All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If one repents from his/her sin, it is as if he/she did not commit the sin at all. It is not permissible for a Muslim to punish a Muslim for the sin he/she had committed in the past and turned away from that sin; also, the signs of giving up that sin are evident from his/her attitude. A Muslim should accept the one whom Allah has accepted.
If this woman has repented, becomes righteous, and continues to follow the rulings of Sharee'ah, then we would advise her husband to continue the conjugal life with her, be good to her, and raise her upon goodness.
For more benefit on the conditions of sincere repentance, please refer to Fatwa 86527.
Allah knows best.