Is refraining from visiting the maternal uncle, who accuses the questioner of adultery with his son and of looking at his daughter, considered a severance of kinship ties after he informed her mother of his unwillingness for her to visit?

Not going is not a severance of kinship ties; rather, it is a preservation of one's honor and a cutting off of the discord that the maternal uncle might incite. Your innocence can be demonstrated over time, and throwing terrible accusations at a Muslim without certainty is impermissible. Cite the verse: "And those who harm believing men and believing women for [something] other than what they have earned have certainly borne a slander and a manifest sin" (Al-Ahzab: 58). We advise patience and endurance.