Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Basically a Muslim is free from bad things. It is obligatory on every Muslim to think well of every Muslim unless the opposite is proved. Allah says:"Why then, did not the believers, men and women, when you heard it (the slander) think good of their own people and say: "This (charge) is an obvious lie?" (An-Nur 24:12)
Therefore, you must think well of your wife and consider her free from what was said about her, particularly since she has denied the charge. It is very possible that those who informed you about your wife are trying to sow distrust between you and your wife as she said. However, do not give any chance to Satan to spoil your relation with your wife and seek Allah's refuge from the trick and plots of Satan.
Imam Muslim narrated from Jabir that the Prophet (Sallallahu Alaihi wa Sallam) said: "Iblees (Satan) places his throne upon water; he then sends detachments (for creating dissension); the nearer to him in rank are those who are most notorious in creating distortion. One of them comes and says: 'I did so and so. And he says "you have done nothing." Then one amongst them comes and says: "I did not spare so and so until I sowed the seed of discord between a husband and a wife." The Satan goes near to him and says: 'you have done well.' He then embraces him."
Therefore, give up the satanic whispers and be with your wife as though nothing happened. Also encourage your wife to adhere to every practice that leads to chastity and that protects from shamelessness such as wearing Hijab, not mixing with opposite sex and staying away from bad places. Try your best to keep your family with you to the extent of your capacity. Also advise those people who informed you about your wife that they are responsible for their actions and thus should not inform of what could spoil amity and friendship between people.
Allah knows best.