I think it is common to make a bracha (blessing) when giving a small child food so that they learn the common brachot and learn to say "amen". Is this appropriate to do if you are not eating the food yourself, or would that be a bracha levatala (a blessing made in vain)?
For example:
A father gets out some cookies, makes a mezonot in front of his three-year old son, who says "amen", and they both eat. No question that it is correct since they both ate the food.
The father then gets out milk and pours it in a cup for the child. He is not planning on having any himself. Should he make a she'hakol so the child can hear the bracha and say amen (chinuch/educational purposes), or would this be wrong since he is not drinking it? Would the answer be different if instead it was his nephew and he thus had no specific obligation to teach him?