Does a sister have the right to claim her share of her father's land that her brother, who was its guardian, sold without her knowledge or without giving her her due, knowing that he will deny it?

Oppressing one's brother and unlawfully consuming his wealth are grave sins. Allah has threatened severe punishment for those who commit such acts. Allah Almighty says: "O you who have believed, do not consume one another's wealth unjustly but only [in lawful] business by mutual consent. And do not kill yourselves. Indeed, Allah is to you ever Merciful. And whoever does that in aggression and injustice – then We will drive him into a Fire. And that, for Allah, is easy." Your brother's children must return your rightful due; otherwise, you have the right to take the matter to court.