What is the ruling on a person marrying someone they desire if their family is unwilling, and is it permissible for them to do so after reaching the legal age without the consent of relatives?

If the suitor is a mature, رشيد (of sound judgment) man, his marriage is valid and enforceable even if his parents do not approve. However, he is not permitted to disobey his parents by delaying the marriage unless he fears hardship for himself. Nor should he violate the law of his country if a penalty would result from such violation. As for a female suitor, she is not permitted to marry without the permission of her guardian, whether or not she has reached the legal age.