Can you wrap up some kind of clue? I got my husband Cotton Bowl tickets once and wrapped up a bowl full of cotton balls. That went over pretty well. It's a little more fun than just handing someone tickets.
I like the idea of wrapping them with a CD, as long as you know it's a CD she doesn't already have.
Or you could just fill a box full of styrofoam peanuts and put them inside. Make her dig for them a little.
Why do people kill people who kill people to show people that to kill people - is bad?