Allah says there is no good in much of people's private talk "except one who enjoins charity, or what is right, or reconciliation between people; and whoever does that seeking the pleasure of Allah, We will give him a great reward" (Quran 4:114), and He commands, "The believers are but brothers, so make reconciliation between your two brothers" (Quran 49:10). The Prophet (ﷺ) taught that setting matters right between people is greater in degree than voluntary fasting, prayer and charity, because the corruption of relations is "the shaver" — it shaves away the religion (Sunan Abi Dawud 4919, authenticated by al-Albani). Because of its weight, the Sharīʿah allows a narrow concession here: "He is not a liar who reconciles between people and conveys good" (al-Bukhari 2692, Muslim 2605) — meaning he may pass on the good each says of the other, and the scholars permit withholding or softening words for this purpose; it does not permit inventing speech that becomes slander, false testimony, or the seizing of someone's right.
Q&A · Character
How much reward is there in reconciling between two people who have fallen out?
Evidence — the daleel
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.