Not me, but someone I know.
She buys it for her DC when they go to a party, and justifies it by saying that as alcohol is very much a feature of parties for that age group, she prefers DC to drink safely rather than drink any old thing they're offered. The DC has been told they can only drink what their mum has given them to take along.
I have not spoken to the mother in question myself, and don't know exactly what she buys for the child, but I have to say I was rather taken aback. It was brought up as part of a discussion with a third party on our own DCs reaching a similar age and how to handle the question of under-age drinking.
Buying if for them would never cross my mind, however maybe I just live a sheltered life.
Is she BU, or does she have a point in doing this?