Is the marriage considered legitimate despite the lack of approval from the wife's parents, and is the approval of the father or guardian a condition for marriage in Islam, and is her father entitled to reject the marriage solely because of the suitor's nationality?

Marriage is not valid without the guardian's permission, according to the Prophet's (peace be upon him) saying: "There is no marriage except with a guardian." The guardian does not have the right to refuse the marriage of his ward on the pretext of different nationalities. Rather, he should marry her off if a suitor who is pleasing in his religion and character comes forward. This is even more emphasized if the girl loves him, for the Prophet (peace be upon him) said: "Nothing like marriage has been seen for those who love each other." If it is proven that the guardian is unjustly preventing her marriage, the girl may take her case to the judge to marry her off.