What is the ruling on buying from one's sister merchandise that was left with her, originally designated for distribution to charitable organizations, then selling it and distributing its price to the poor and needy?

The sister must distribute the goods according to the agency: she should sell them and distribute their price among the families and Qur'an memorization circles if she is authorized to do so; otherwise, she should distribute them as they are. It is not permissible for her to buy anything from them except with the permission of the principal, provided that she does not favor herself.