The Transactions of the Child
Question :

I understand from the books of His Eminence that the buyer and seller in a transaction have to be adults (baligh). Does this mean that parents cannot send their children to the store to buy something? Or children in school cannot buy food from the cafeteria?

Answer :

It is permissible for the child to buy or sell if it was with the consent of the guardian.

Buying from Someone who Sells Alcohol
Question :

Could one buy goods from someone who sells Alcohol in his shop?

Answer :

Yes, but it is better to choose shops that do not sell such prohibited items.