OP, I hope you have recanted and are now having three nice girls for pizza and sleepover.
If not...
The vodka. Oh, the vodka. Ban it all you like, but there will still be a litre bottle hidden (in advance) somewhere in your garden/garage/outhouse/under a flowerpot. If not one litre, several of the bastards.
Confiscate all bottles of mineral water, because they won't be mineral water. In fact, confiscate any soft drink which has already had the top opened.
Do not provide alcohol. They will do this for you, despite the above precautions. And some parents will not thank you for providing it.
Nobody upstairs under any circumstances whatsoever. That includes you. You need to be lurking where you can see what's happening. Agree that guarding the stairs is a good idea.
Remove anything that can be moved. Including furniture.
Expect the entire contents of your fridge, freezer and cupboards to be eaten/thrown around the garden/thrown up.
Provide as many buckets as you like, but nobody will be sick into them. The carpet, if you have one, will be the lucky receptacle.
Provide lots of kitchen roll and loo roll because it's, like, really good fun to stick it under the tap and throw it at your friends.
Do not provide Cillit Bang or such like, as someone will drink it/get it in their eyes.
Don't drink yourself, tempting as it is to drown the awfulness of the whole event. You will need to be able to drive.
Don't rely on Ubers/taxis. Not their fault at all - but once they start turning up (sensibly pre-booked by parents/you etc), whichever sloshed teenagers who happen to be near them will tip themselves into them. Cue pandemonium.
Your DD sounds like a lovely and sensible girl, btw. Does she really want this as a birthday/post exam celebration? I have one who's just finished GCSEs. He wanted a house party here. Not bloody likely.