What is the ruling on a father who does not see his daughter from his ex-wife, does not ask about her, and has not fulfilled his obligations in court for 5 years, and is the mother sinful for initially preventing the father from visiting due to his failure to financially support the daughter?

The mother does not have the right to prevent her ex-husband from seeing their daughter, because by doing so, she would be unjust, sinful, and severing ties of kinship. She must repent. Likewise, the father must visit his daughter and spend on her if she is in need of that. Neither parent has the right to influence the children to prevent them from connecting with the other party.