All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
In principle, a Muslim - whether man or woman - is not a sinner unless proven otherwise. It is impermissible to accuse a Muslim of any disgraceful deed or sin without clear evidence and this is considered a kind of mistrust of one's fellow Muslims (which is impermissible).
This is even more emphasized when it comes to the spouses, given the sacredness of the bond of matrimony. For more benefit, please refer to Fataawa 84632 and 87877. When a husband suspects his wife for no reason, it is considered a blameworthy form of protective jealousy. However, if there is clear evidence or strong reasons for having such doubts, and indications on the wife’s unfaithfulness that undermines her honor and that of her husband, then it is considered a praiseworthy protective jealousy. Verily, a man who does not show protective jealousy for his wife's honor is labeled as Dayyooth (cuckold). Such a man is promised a severe punishment; please refer to Fatwa 82073.
Dear questioner, it is odd that you did not ask about the relevant rulings regarding your wife’s conduct in this worldly life and crossed directly to the Hereafter!
If a husband is suspicious of his wife’s conduct, he should kindly and leniently advise her; perhaps she would listen and come back to her senses. If she did, it would be great, all praise be to Allaah; otherwise, if she proved persistent and refused to stop her disgraceful conduct, then it is recommended for you to divorce her. In this case, perhaps it is even obligatory for you to divorce her. Ibn Qudaamah wrote about the categories of divorce: “The fourth category is recommended; this is when the wife neglects the rights of Allaah such as observing the prayer or the like of the religious obligations and the husband cannot oblige her to fulfill those rights, or when she is an unchaste woman. Imaam Ahmad said, ‘In this case, it is incumbent on the husband to divorce her because keeping her undermines his religiosity and he cannot guarantee her faithfulness; she may even attribute another man's child to him. In this case, there is no harm in making life difficult for her in order to drive her to demand Khul‘; Allaah, The Exalted, says (what means): {…And do not make difficulties for them in order to take [back] part of what you gave them unless they commit a clear immorality...}[Quran 4:19] Divorce in these two cases may be even obligatory on the husband.”
On the other hand, you should know that life in Paradise is totally different from that of the world; the Hereafter should not be judged according to worldly standards. There is no room for such questions you have raised. In fact, raising these questions is considered a sort of intellectual excess that a Muslim should avoid. If the two spouses entered Paradise, their marriage will continue and she will be dearer to him than all the Hooris (damsels of Paradise). Therefore, you should ask your Lord to bless you and your wife with Paradise.
Finally, we referred you earlier to the Fatwa about the meaning of Dayyooth (cuckold). Please refer to Fatwa 232012 about the meaning of sinning openly and to Fatwa 86527 about Huqooq Al-'Ibaad (repentance of sins related to wronging people and violating their rights).
Allaah Knows best.