Is the marriage valid if a woman marries without the consent of her guardian (father), who rejected the man due to his bad character, and her marriage resulted from her elopement?

The father did well by refusing to marry his daughter to a man of bad character. As for the sister, she did wrong by poorly choosing to run away from her father's house and marry without a guardian. Her marriage is invalid according to Sharia, as the guardian's consent is a pillar of a valid marriage, as indicated by texts from the Holy Quran and the Prophet's Sunnah. Therefore, the sister must repent, seek forgiveness, and return to her father. She must not remain with this man because he is not her legal husband. Either the marriage contract is renewed with her guardian's presence if he agrees, or the contract is automatically dissolved if the father does not agree, and her father chooses for her someone he approves of among people of religion and good character.