How can a father be persuaded to approve his eldest daughter's (33 years old) marriage to a divorced man with an 8-year-old child, despite the daughter's conviction about the man's character and religiosity?

A father does not have the right to prevent his daughter from marrying a suitable man (kufu'), and he must fear Allah and not prevent her. The girl can express her desire to her father and seek help from someone who can persuade him. She should also supplicate and be content with Allah's decree, for the best of matters is what Allah has chosen.