Alc is a stimulant in low doses and as said she’d need a large dose to reap the depressant dose which could be dangerous regarding her age and if she’s taken a sleeper with it and has forgotten.
Have you tried l theanine or l tryptophan, I’ve used both in a hot mug of milk before bed with great success.
Unfortunately, the soporific effects of small amounts of alcohol tend to be short-lived so while it might make her go off to sleep in the short-term ,if she awakens from sleeping tablets she is also likely to wake up in the middle of the night after alcohol.
I think it when people have a lot of alcohol that they tend to go to sleep and then wake up again. In my experience, if I give them a couple of glasses of a good red, they tend to be comatose for about 6 hours
I have been on sleeping tablets (Temazapam) for 8 years, to help me Not, drink. They worked and these days, if I do have a drink with my sleeping pills, they have the exact opposite affect. I always have a lousy nights sleep.
This sounds silly, but my grandson doesn't sleep well and the school nurse suggested cherry juice which has something soporific in it. Could be worth a try too.