Just to be technically correct in reproducing what the "Society" say.
WT Dec 1st 01 "Questions From Readers"
Since the person is no longer in the congregation, any change in heart and attitude may be observed first by those close to him, such as a marriage mate or family members. Those observing such changes may conclude that the transgressor did not commit a sin that incurs death. They may be moved to pray that he may draw strength from God’s inspired Word and that Jehovah will act toward the sinner in harmony with His will.—Psalm 44:21; Ecclesiastes 12:14.
While some may be in a position to observe sufficient evidence to believe that the sinner has repented, this may not be the case with the congregation in general. They would be puzzled, troubled, even stumbled if they were to hear someone praying publicly about the erring one. For this reason, those who feel moved to pray about the sinner should do so only in private, leaving any further development in the matter in the hands of the responsible elders in the congregation."
However, it is generally held, even now, that one does not pray for the disfellowshipped . They say that they are worse than worldly people since they have "returned to the low sink of debauchery"
I recall talking to a distessed "sister" who had a d'f' daughter and I told her that her prayers were between her and God alone and no man could tell her what to say