Is going for Hajj considered a sin or an transgression, given the parents' estrangement and sorrow, their disapproval of the husband, and their refusal of any reconciliation except through divorcing the husband?

May you be rewarded with goodness for your patience and your efforts to reform your family. Continue to maintain ties with them and treat them with kindness, especially your father and mother, for your dutifulness to them does not cease due to their ill-treatment. Do not obey them in their request for you to divorce your husband without a valid Shar’i reason, for it has been authentically reported from the Prophet (peace be upon him): "Any woman who asks her husband for a divorce without a valid reason, the scent of Paradise will be forbidden to her." Their request for this is a form of forbidden incitement (takhbib), and the Prophet (peace be upon him) said: "He is not one of us who incites a woman against her husband." Preserve your noble husband, maintain ties with your parents, treat your siblings with kindness, and strive in supplication.