In most places, 18 years of age is the legal age at which you can play the lottery. Perhaps going out for a day of shopping and end it off with a pile of scratch tickets and hope for a big win!
Take your daughter to a casino with a couple of her over 18 friends, and give her $100 to spend at the tables, then rent a hotel room for her and her friends.
When your loved one turns 18 and you want to do something special for them on their birthday, you should get them a present they could never get on their own like a nice computer or even better a new car.