Help! Busted by my daughter!?

So I'm a secret smoker (I know, it's stupid and I'm trying to quit, but anyway...). I've hidden this from my kids because I hate to set a bad example. But my 15-year-old daughter found my cigarettes hidden in a drawer. She hasn't said anything, but I know she found them. And I'd been planning on telling her (if she asked) that they were her aunt's from the last time she visited and that I just never threw them away. But I apparently she went and looked again... and I overheard her telling her friend that she'd checked and found some more gone. So I'm totally busted! Ahhhhh what should I do?? I REALLY don't want to have to tell her the truth, but I can't think of any way to get out of it. She's going to be so disappointed and disgusted with me. (Well, I guess she already is). PLEASE HELP!