Is it permissible for a girl to marry a man younger than her, especially if he is of good character and religious commitment? And are the parents allowed to reject this marriage merely due to the age difference, knowing that the girl fears missing the age of marriage?

We advise you to be patient and content with Allah's decree, for every decree Allah ordains is good for the believer. Your family's rejection of a suitor who possesses good character and religious commitment is not permissible and violates the command of the Messenger of Allah, peace and blessings be upon him: "If someone whose character and religious commitment you are pleased with comes to you, then marry him." The guardianship of the father is forfeited if he refuses to marry off his daughter to a suitable suitor without a valid reason, and guardianship then transfers to the next of kin among the guardians or to the judge. Mocking others is forbidden, but we advise you to forgive your sister and consider her circumstances. Honoring one's parents is obligatory, but if they persist in their obstinacy regarding your marriage, and mediations are unsuccessful, then refer your matter to the judiciary.