Is the wife considered sinful for relinquishing her inheritance from her father, despite the objection of her husband who fears that her brothers will deny his right to a piece of land he bought from her father and which was not officially registered?

A woman has the right to dispose of her own wealth if she is of sound mind. However, good marital relations entail informing her husband of this, especially if it affects his right to inheritance. Since you have relinquished your inheritance, you should appease your husband and remind your brothers of his right to the land, for people's rights are serious and must not be denied.