Ignore all the very naive 'none' people. If there's booze there and she wants some, she'll be having some.
Also, ignore everyone else. There's no right answer here.
Are the parents there going to be keeping an eye on things, or disappearing upstairs and turning a blind eye?
Is your daughter sensible enough to drink only what you send her with? Is she mature enough to understand that you're essentially giving her the freedom of an adult, and that she'll be expected to behave like an adult as a result, and deal with adult consequences if she doesn't? Are you willing to enforce those rules/consequences?
Is she used to drinking alcohol? Does she know her limits?
I grew up in a European country where you could legally drink beer/wine in bars/buy it from supermarkets age 16. My parents were fine with me having a few beers/Smirnoff Ice or whatever with friends from 15. We could blag bars/shops at that age with a bit of makeup/fancy clothes, so there wasn't much they could do about it anyway.
We worked on a trust system: If I had a couple of drinks and came home at a reasonable time in a reasonable state, they were happy to treat me like a young adult. If I came home drunk or late or didn't answer my phone, the consequence was being treated like a child.