What is the path to repentance from committing adultery with a married woman, which resulted in the birth of a child attributed to her husband, knowing the complexity of the relationships and the difficulty of the matter, and is there any repentance for the adulterer and the wife?

The lineage of this daughter is attributed to the woman's husband, unless he denies it through li'an (oath of condemnation), based on the Prophet's (peace be upon him) saying: "The child is for the bed, and for the fornicator is the stone (deprivation)." It is obligatory upon you to hasten to sincere repentance to Allah, the Almighty, for the crime of zina (unlawful sexual intercourse), and to strive in drawing closer to Him through righteous deeds, so that Allah may forgive you. Allah, the Exalted, says: "And those who do not invoke with Allah another deity or kill the soul which Allah has forbidden [to be killed], except by right, and do not commit unlawful sexual intercourse. And whoever does that will meet a penalty. Multiplied for him will be the punishment on the Day of Resurrection, and he will abide therein disgraced. Except for those who repent, believe and do righteous work. For them Allah will change their evil deeds into good ones. And ever is Allah Forgiving and Merciful." And part of the completeness of your repentance is to completely sever your relationship with this woman.