Is a wife's act of donating old clothes without her husband's knowledge considered a sin that warrants accountability, and what should a wife do if she has beautiful clothes that she does not wish to leave unused, but fears her husband's anger if she donates them?

There is no harm in a wife giving away her used clothes in charity without her husband's permission, because she owns her sustenance and clothing upon receiving them, and she may dispose of them as she wishes. As for the children's used clothes, it is not permissible to give them away in charity without the husband's permission. If she had previously disposed of them out of ignorance of the ruling, we hope there is no sin upon her, and she should seek her husband's permission and come to an understanding with him.