What is the ruling of Islamic law regarding the family dispute that arose due to a girl marrying her fiancé, whom her father had rejected, and her eloping with him and marrying him عرفيًا (according to customary practice), then formalizing the marriage officially, while the father is angry and has ostracized his children because of the grandmother who supported his granddaughter's marriage and covered for her, knowing that the grandmother wishes to know Allah's ruling regarding forgiving her daughter (the girl's mother)?

The grandmother erred in helping her granddaughter communicate with the suitor, go out with him, and then marry him secretly without a guardian. Her cutting off her daughter is a major sin. The girl should have referred her case to the judiciary if her father prevented her marriage. The granddaughter and grandmother must repent to Allah. The daughter must be dutiful to her mother, even if she has wronged her. The grandchildren must maintain ties with their grandmother, even if their father instructs them to cut her off, and they should combine dutifulness to their father with maintaining ties to their grandmother without his knowledge. Righteous people should intervene to reconcile them.