I am an orphan, and a young man proposed to me, but my uncles rejected him because my older sister has not yet been proposed to. Is this permissible?

Question:
She says: I am a twenty-year-old girl, an orphan of both parents. A young man proposed to me, as he is a man of religion and high moral character with an excellent job, and I also have a high level of education. When he approached my uncles, they rejected him on the grounds that I have an older sister. They rejected him. I am a girl who seeks good from Allah, hoping that a young man like him will propose to me. When he did, I was very happy because I would be living with a man who protects me and provides for me, especially since I am an orphan. Is this rejection by my uncles, which has no reason, valid? Should I go to the judge in our town with this claim? Is it the case that every young man who proposes to me is rejected because of this? Please advise us, may Allah reward you with good. Is it valid for my maternal uncles to also do this, to marry me off to that young man, and for my guardianship to transfer to my maternal uncles? May Allah reward you with good, and may Allah reward you.

Answer:
In the name of Allah, the Most Gracious, the Most Merciful. Praise be to Allah, Lord of the worlds, and may Allah send prayers and blessings upon our Prophet Muhammad, and upon his family and his Companions. To proceed: There is no doubt that marrying a woman to a suitable, righteous man who has proposed to her is a precious opportunity, and there is much good in seizing it, as the Messenger (peace and blessings be upon him) said: .
As for the issue of marrying the younger sister before the older one, this issue has no basis in the Shari'ah. People observe this custom to console the older sister, and also because marrying the younger sister might cause suitors to turn away from the older one, as they might say, "If the older one were desirable, they would not have looked past her." For this reason, people have observed this custom. However, from the perspective of the Shari'ah, there is no blame on marrying the girl to the suitable man who proposed to her, whether she is the younger or the older sister. I hope that the matter does not reach the stage of litigation before the judge, and that the awliya (guardians) of the questioner look into the benefit and choose the useful method. If they intend that, then Allah the Exalted will help them.